Merge branch 'tracing-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (131 commits)
  tracing/fastboot: improve help text
  tracing/stacktrace: improve help text
  tracing/fastboot: fix initcalls disposition in bootgraph.pl
  tracing/fastboot: fix bootgraph.pl initcall name regexp
  tracing/fastboot: fix issues and improve output of bootgraph.pl
  tracepoints: synchronize unregister static inline
  tracepoints: tracepoint_synchronize_unregister()
  ftrace: make ftrace_test_p6nop disassembler-friendly
  markers: fix synchronize marker unregister static inline
  tracing/fastboot: add better resolution to initcall debug/tracing
  trace: add build-time check to avoid overrunning hex buffer
  ftrace: fix hex output mode of ftrace
  tracing/fastboot: fix initcalls disposition in bootgraph.pl
  tracing/fastboot: fix printk format typo in boot tracer
  ftrace: return an error when setting a nonexistent tracer
  ftrace: make some tracers reentrant
  ring-buffer: make reentrant
  ring-buffer: move page indexes into page headers
  tracing/fastboot: only trace non-module initcalls
  ftrace: move pc counter in irqtrace
  ...

Manually fix conflicts:
 - init/main.c: initcall tracing
 - kernel/module.c: verbose level vs tracepoints
 - scripts/bootgraph.pl: fallout from cherry-picking commits.

16 files changed, 4102 insertions, 1318 deletions

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 263e9e6..1cb3e1f 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -1,23 +1,37 @@
 #
 # Architectures that offer an FTRACE implementation should select HAVE_FTRACE:
 #
+
+config NOP_TRACER
+	bool
+
 config HAVE_FTRACE
 	bool
+	select NOP_TRACER
 
 config HAVE_DYNAMIC_FTRACE
 	bool
 
+config HAVE_FTRACE_MCOUNT_RECORD
+	bool
+
 config TRACER_MAX_TRACE
 	bool
 
+config RING_BUFFER
+	bool
+
 config TRACING
 	bool
 	select DEBUG_FS
+	select RING_BUFFER
 	select STACKTRACE
+	select TRACEPOINTS
 
 config FTRACE
 	bool "Kernel Function Tracer"
 	depends on HAVE_FTRACE
+	depends on DEBUG_KERNEL
 	select FRAME_POINTER
 	select TRACING
 	select CONTEXT_SWITCH_TRACER
@@ -36,6 +50,7 @@ config IRQSOFF_TRACER
 	depends on TRACE_IRQFLAGS_SUPPORT
 	depends on GENERIC_TIME
 	depends on HAVE_FTRACE
+	depends on DEBUG_KERNEL
 	select TRACE_IRQFLAGS
 	select TRACING
 	select TRACER_MAX_TRACE
@@ -59,6 +74,7 @@ config PREEMPT_TRACER
 	depends on GENERIC_TIME
 	depends on PREEMPT
 	depends on HAVE_FTRACE
+	depends on DEBUG_KERNEL
 	select TRACING
 	select TRACER_MAX_TRACE
 	help
@@ -86,6 +102,7 @@ config SYSPROF_TRACER
 config SCHED_TRACER
 	bool "Scheduling Latency Tracer"
 	depends on HAVE_FTRACE
+	depends on DEBUG_KERNEL
 	select TRACING
 	select CONTEXT_SWITCH_TRACER
 	select TRACER_MAX_TRACE
@@ -96,16 +113,56 @@ config SCHED_TRACER
 config CONTEXT_SWITCH_TRACER
 	bool "Trace process context switches"
 	depends on HAVE_FTRACE
+	depends on DEBUG_KERNEL
 	select TRACING
 	select MARKERS
 	help
 	  This tracer gets called from the context switch and records
 	  all switching of tasks.
 
+config BOOT_TRACER
+	bool "Trace boot initcalls"
+	depends on HAVE_FTRACE
+	depends on DEBUG_KERNEL
+	select TRACING
+	help
+	  This tracer helps developers to optimize boot times: it records
+	  the timings of the initcalls and traces key events and the identity
+	  of tasks that can cause boot delays, such as context-switches.
+
+	  Its aim is to be parsed by the /scripts/bootgraph.pl tool to
+	  produce pretty graphics about boot inefficiencies, giving a visual
+	  representation of the delays during initcalls - but the raw
+	  /debug/tracing/trace text output is readable too.
+
+	  ( Note that tracing self tests can't be enabled if this tracer is
+	    selected, because the self-tests are an initcall as well and that
+	    would invalidate the boot trace. )
+
+config STACK_TRACER
+	bool "Trace max stack"
+	depends on HAVE_FTRACE
+	depends on DEBUG_KERNEL
+	select FTRACE
+	select STACKTRACE
+	help
+	  This special tracer records the maximum stack footprint of the
+	  kernel and displays it in debugfs/tracing/stack_trace.
+
+	  This tracer works by hooking into every function call that the
+	  kernel executes, and keeping a maximum stack depth value and
+	  stack-trace saved. Because this logic has to execute in every
+	  kernel function, all the time, this option can slow down the
+	  kernel measurably and is generally intended for kernel
+	  developers only.
+
+	  Say N if unsure.
+
 config DYNAMIC_FTRACE
 	bool "enable/disable ftrace tracepoints dynamically"
 	depends on FTRACE
 	depends on HAVE_DYNAMIC_FTRACE
+	depends on DEBUG_KERNEL
 	default y
 	help
          This option will modify all the calls to ftrace dynamically
@@ -121,12 +178,17 @@ config DYNAMIC_FTRACE
 	 were made. If so, it runs stop_machine (stops all CPUS)
 	 and modifies the code to jump over the call to ftrace.
 
+config FTRACE_MCOUNT_RECORD
+	def_bool y
+	depends on DYNAMIC_FTRACE
+	depends on HAVE_FTRACE_MCOUNT_RECORD
+
 config FTRACE_SELFTEST
 	bool
 
 config FTRACE_STARTUP_TEST
 	bool "Perform a startup test on ftrace"
-	depends on TRACING
+	depends on TRACING && DEBUG_KERNEL && !BOOT_TRACER
 	select FTRACE_SELFTEST
 	help
 	  This option performs a series of startup tests on ftrace. On bootup
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 71d17de..a85dfba 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -11,6 +11,7 @@ obj-y += trace_selftest_dynamic.o
 endif
 
 obj-$(CONFIG_FTRACE) += libftrace.o
+obj-$(CONFIG_RING_BUFFER) += ring_buffer.o
 
 obj-$(CONFIG_TRACING) += trace.o
 obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o
@@ -19,6 +20,9 @@ obj-$(CONFIG_FTRACE) += trace_functions.o
 obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o
 obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o
 obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o
+obj-$(CONFIG_NOP_TRACER) += trace_nop.o
+obj-$(CONFIG_STACK_TRACER) += trace_stack.o
 obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
+obj-$(CONFIG_BOOT_TRACER) += trace_boot.o
 
 libftrace-y := ftrace.o
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index f6e3af3..4dda4f6 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -81,7 +81,7 @@ void clear_ftrace_function(void)
 
 static int __register_ftrace_function(struct ftrace_ops *ops)
 {
-	/* Should never be called by interrupts */
+	/* should not be called from interrupt context */
 	spin_lock(&ftrace_lock);
 
 	ops->next = ftrace_list;
@@ -115,6 +115,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
 	struct ftrace_ops **p;
 	int ret = 0;
 
+	/* should not be called from interrupt context */
 	spin_lock(&ftrace_lock);
 
 	/*
@@ -153,6 +154,30 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 
+#ifndef CONFIG_FTRACE_MCOUNT_RECORD
+/*
+ * The hash lock is only needed when the recording of the mcount
+ * callers are dynamic. That is, by the caller themselves and
+ * not recorded via the compilation.
+ */
+static DEFINE_SPINLOCK(ftrace_hash_lock);
+#define ftrace_hash_lock(flags)	  spin_lock_irqsave(&ftrace_hash_lock, flags)
+#define ftrace_hash_unlock(flags) \
+			spin_unlock_irqrestore(&ftrace_hash_lock, flags)
+#else
+/* This is protected via the ftrace_lock with MCOUNT_RECORD. */
+#define ftrace_hash_lock(flags)   do { (void)(flags); } while (0)
+#define ftrace_hash_unlock(flags) do { } while(0)
+#endif
+
+/*
+ * Since MCOUNT_ADDR may point to mcount itself, we do not want
+ * to get it confused by reading a reference in the code as we
+ * are parsing on objcopy output of text. Use a variable for
+ * it instead.
+ */
+static unsigned long mcount_addr = MCOUNT_ADDR;
+
 static struct task_struct *ftraced_task;
 
 enum {
@@ -171,7 +196,6 @@ static struct hlist_head ftrace_hash[FTRACE_HASHSIZE];
 
 static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu);
 
-static DEFINE_SPINLOCK(ftrace_shutdown_lock);
 static DEFINE_MUTEX(ftraced_lock);
 static DEFINE_MUTEX(ftrace_regex_lock);
 
@@ -294,13 +318,37 @@ static inline void ftrace_del_hash(struct dyn_ftrace *node)
 
 static void ftrace_free_rec(struct dyn_ftrace *rec)
 {
-	/* no locking, only called from kstop_machine */
-
 	rec->ip = (unsigned long)ftrace_free_records;
 	ftrace_free_records = rec;
 	rec->flags |= FTRACE_FL_FREE;
 }
 
+void ftrace_release(void *start, unsigned long size)
+{
+	struct dyn_ftrace *rec;
+	struct ftrace_page *pg;
+	unsigned long s = (unsigned long)start;
+	unsigned long e = s + size;
+	int i;
+
+	if (ftrace_disabled || !start)
+		return;
+
+	/* should not be called from interrupt context */
+	spin_lock(&ftrace_lock);
+
+	for (pg = ftrace_pages_start; pg; pg = pg->next) {
+		for (i = 0; i < pg->index; i++) {
+			rec = &pg->records[i];
+
+			if ((rec->ip >= s) && (rec->ip < e))
+				ftrace_free_rec(rec);
+		}
+	}
+	spin_unlock(&ftrace_lock);
+
+}
+
 static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
 {
 	struct dyn_ftrace *rec;
@@ -338,7 +386,6 @@ ftrace_record_ip(unsigned long ip)
 	unsigned long flags;
 	unsigned long key;
 	int resched;
-	int atomic;
 	int cpu;
 
 	if (!ftrace_enabled || ftrace_disabled)
@@ -368,9 +415,7 @@ ftrace_record_ip(unsigned long ip)
 	if (ftrace_ip_in_hash(ip, key))
 		goto out;
 
-	atomic = irqs_disabled();
-
-	spin_lock_irqsave(&ftrace_shutdown_lock, flags);
+	ftrace_hash_lock(flags);
 
 	/* This ip may have hit the hash before the lock */
 	if (ftrace_ip_in_hash(ip, key))
@@ -387,7 +432,7 @@ ftrace_record_ip(unsigned long ip)
 	ftraced_trigger = 1;
 
  out_unlock:
-	spin_unlock_irqrestore(&ftrace_shutdown_lock, flags);
+	ftrace_hash_unlock(flags);
  out:
 	per_cpu(ftrace_shutdown_disable_cpu, cpu)--;
 
@@ -531,6 +576,16 @@ static void ftrace_shutdown_replenish(void)
 	ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL);
 }
 
+static void print_ip_ins(const char *fmt, unsigned char *p)
+{
+	int i;
+
+	printk(KERN_CONT "%s", fmt);
+
+	for (i = 0; i < MCOUNT_INSN_SIZE; i++)
+		printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
+}
+
 static int
 ftrace_code_disable(struct dyn_ftrace *rec)
 {
@@ -541,10 +596,27 @@ ftrace_code_disable(struct dyn_ftrace *rec)
 	ip = rec->ip;
 
 	nop = ftrace_nop_replace();
-	call = ftrace_call_replace(ip, MCOUNT_ADDR);
+	call = ftrace_call_replace(ip, mcount_addr);
 
 	failed = ftrace_modify_code(ip, call, nop);
 	if (failed) {
+		switch (failed) {
+		case 1:
+			WARN_ON_ONCE(1);
+			pr_info("ftrace faulted on modifying ");
+			print_ip_sym(ip);
+			break;
+		case 2:
+			WARN_ON_ONCE(1);
+			pr_info("ftrace failed to modify ");
+			print_ip_sym(ip);
+			print_ip_ins(" expected: ", call);
+			print_ip_ins(" actual: ", (unsigned char *)ip);
+			print_ip_ins(" replace: ", nop);
+			printk(KERN_CONT "\n");
+			break;
+		}
+
 		rec->flags |= FTRACE_FL_FAILED;
 		return 0;
 	}
@@ -792,47 +864,7 @@ static int ftrace_update_code(void)
 	return 1;
 }
 
-static int ftraced(void *ignore)
-{
-	unsigned long usecs;
-
-	while (!kthread_should_stop()) {
-
-		set_current_state(TASK_INTERRUPTIBLE);
-
-		/* check once a second */
-		schedule_timeout(HZ);
-
-		if (unlikely(ftrace_disabled))
-			continue;
-
-		mutex_lock(&ftrace_sysctl_lock);
-		mutex_lock(&ftraced_lock);
-		if (!ftraced_suspend && !ftraced_stop &&
-		    ftrace_update_code()) {
-			usecs = nsecs_to_usecs(ftrace_update_time);
-			if (ftrace_update_tot_cnt > 100000) {
-				ftrace_update_tot_cnt = 0;
-				pr_info("hm, dftrace overflow: %lu change%s"
-					" (%lu total) in %lu usec%s\n",
-					ftrace_update_cnt,
-					ftrace_update_cnt != 1 ? "s" : "",
-					ftrace_update_tot_cnt,
-					usecs, usecs != 1 ? "s" : "");
-				ftrace_disabled = 1;
-				WARN_ON_ONCE(1);
-			}
-		}
-		mutex_unlock(&ftraced_lock);
-		mutex_unlock(&ftrace_sysctl_lock);
-
-		ftrace_shutdown_replenish();
-	}
-	__set_current_state(TASK_RUNNING);
-	return 0;
-}
-
-static int __init ftrace_dyn_table_alloc(void)
+static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
 {
 	struct ftrace_page *pg;
 	int cnt;
@@ -859,7 +891,9 @@ static int __init ftrace_dyn_table_alloc(void)
 
 	pg = ftrace_pages = ftrace_pages_start;
 
-	cnt = NR_TO_INIT / ENTRIES_PER_PAGE;
+	cnt = num_to_init / ENTRIES_PER_PAGE;
+	pr_info("ftrace: allocating %ld hash entries in %d pages\n",
+		num_to_init, cnt);
 
 	for (i = 0; i < cnt; i++) {
 		pg->next = (void *)get_zeroed_page(GFP_KERNEL);
@@ -901,6 +935,8 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
 
 	(*pos)++;
 
+	/* should not be called from interrupt context */
+	spin_lock(&ftrace_lock);
  retry:
 	if (iter->idx >= iter->pg->index) {
 		if (iter->pg->next) {
@@ -910,15 +946,13 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
 		}
 	} else {
 		rec = &iter->pg->records[iter->idx++];
-		if ((!(iter->flags & FTRACE_ITER_FAILURES) &&
+		if ((rec->flags & FTRACE_FL_FREE) ||
+
+		    (!(iter->flags & FTRACE_ITER_FAILURES) &&
 		     (rec->flags & FTRACE_FL_FAILED)) ||
 
 		    ((iter->flags & FTRACE_ITER_FAILURES) &&
-		     (!(rec->flags & FTRACE_FL_FAILED) ||
-		      (rec->flags & FTRACE_FL_FREE))) ||
-
-		    ((iter->flags & FTRACE_ITER_FILTER) &&
-		     !(rec->flags & FTRACE_FL_FILTER)) ||
+		     !(rec->flags & FTRACE_FL_FAILED)) ||
 
 		    ((iter->flags & FTRACE_ITER_NOTRACE) &&
 		     !(rec->flags & FTRACE_FL_NOTRACE))) {
@@ -926,6 +960,7 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
 			goto retry;
 		}
 	}
+	spin_unlock(&ftrace_lock);
 
 	iter->pos = *pos;
 
@@ -1039,8 +1074,8 @@ static void ftrace_filter_reset(int enable)
 	unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
 	unsigned i;
 
-	/* keep kstop machine from running */
-	preempt_disable();
+	/* should not be called from interrupt context */
+	spin_lock(&ftrace_lock);
 	if (enable)
 		ftrace_filtered = 0;
 	pg = ftrace_pages_start;
@@ -1053,7 +1088,7 @@ static void ftrace_filter_reset(int enable)
 		}
 		pg = pg->next;
 	}
-	preempt_enable();
+	spin_unlock(&ftrace_lock);
 }
 
 static int
@@ -1165,8 +1200,8 @@ ftrace_match(unsigned char *buff, int len, int enable)
 		}
 	}
 
-	/* keep kstop machine from running */
-	preempt_disable();
+	/* should not be called from interrupt context */
+	spin_lock(&ftrace_lock);
 	if (enable)
 		ftrace_filtered = 1;
 	pg = ftrace_pages_start;
@@ -1203,7 +1238,7 @@ ftrace_match(unsigned char *buff, int len, int enable)
 		}
 		pg = pg->next;
 	}
-	preempt_enable();
+	spin_unlock(&ftrace_lock);
 }
 
 static ssize_t
@@ -1556,6 +1591,114 @@ static __init int ftrace_init_debugfs(void)
 
 fs_initcall(ftrace_init_debugfs);
 
+#ifdef CONFIG_FTRACE_MCOUNT_RECORD
+static int ftrace_convert_nops(unsigned long *start,
+			       unsigned long *end)
+{
+	unsigned long *p;
+	unsigned long addr;
+	unsigned long flags;
+
+	p = start;
+	while (p < end) {
+		addr = ftrace_call_adjust(*p++);
+		/* should not be called from interrupt context */
+		spin_lock(&ftrace_lock);
+		ftrace_record_ip(addr);
+		spin_unlock(&ftrace_lock);
+		ftrace_shutdown_replenish();
+	}
+
+	/* p is ignored */
+	local_irq_save(flags);
+	__ftrace_update_code(p);
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+void ftrace_init_module(unsigned long *start, unsigned long *end)
+{
+	if (ftrace_disabled || start == end)
+		return;
+	ftrace_convert_nops(start, end);
+}
+
+extern unsigned long __start_mcount_loc[];
+extern unsigned long __stop_mcount_loc[];
+
+void __init ftrace_init(void)
+{
+	unsigned long count, addr, flags;
+	int ret;
+
+	/* Keep the ftrace pointer to the stub */
+	addr = (unsigned long)ftrace_stub;
+
+	local_irq_save(flags);
+	ftrace_dyn_arch_init(&addr);
+	local_irq_restore(flags);
+
+	/* ftrace_dyn_arch_init places the return code in addr */
+	if (addr)
+		goto failed;
+
+	count = __stop_mcount_loc - __start_mcount_loc;
+
+	ret = ftrace_dyn_table_alloc(count);
+	if (ret)
+		goto failed;
+
+	last_ftrace_enabled = ftrace_enabled = 1;
+
+	ret = ftrace_convert_nops(__start_mcount_loc,
+				  __stop_mcount_loc);
+
+	return;
+ failed:
+	ftrace_disabled = 1;
+}
+#else /* CONFIG_FTRACE_MCOUNT_RECORD */
+static int ftraced(void *ignore)
+{
+	unsigned long usecs;
+
+	while (!kthread_should_stop()) {
+
+		set_current_state(TASK_INTERRUPTIBLE);
+
+		/* check once a second */
+		schedule_timeout(HZ);
+
+		if (unlikely(ftrace_disabled))
+			continue;
+
+		mutex_lock(&ftrace_sysctl_lock);
+		mutex_lock(&ftraced_lock);
+		if (!ftraced_suspend && !ftraced_stop &&
+		    ftrace_update_code()) {
+			usecs = nsecs_to_usecs(ftrace_update_time);
+			if (ftrace_update_tot_cnt > 100000) {
+				ftrace_update_tot_cnt = 0;
+				pr_info("hm, dftrace overflow: %lu change%s"
+					" (%lu total) in %lu usec%s\n",
+					ftrace_update_cnt,
+					ftrace_update_cnt != 1 ? "s" : "",
+					ftrace_update_tot_cnt,
+					usecs, usecs != 1 ? "s" : "");
+				ftrace_disabled = 1;
+				WARN_ON_ONCE(1);
+			}
+		}
+		mutex_unlock(&ftraced_lock);
+		mutex_unlock(&ftrace_sysctl_lock);
+
+		ftrace_shutdown_replenish();
+	}
+	__set_current_state(TASK_RUNNING);
+	return 0;
+}
+
 static int __init ftrace_dynamic_init(void)
 {
 	struct task_struct *p;
@@ -1572,7 +1715,7 @@ static int __init ftrace_dynamic_init(void)
 		goto failed;
 	}
 
-	ret = ftrace_dyn_table_alloc();
+	ret = ftrace_dyn_table_alloc(NR_TO_INIT);
 	if (ret)
 		goto failed;
 
@@ -1593,6 +1736,8 @@ static int __init ftrace_dynamic_init(void)
 }
 
 core_initcall(ftrace_dynamic_init);
+#endif /* CONFIG_FTRACE_MCOUNT_RECORD */
+
 #else
 # define ftrace_startup()		do { } while (0)
 # define ftrace_shutdown()		do { } while (0)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
new file mode 100644
index 0000000..94af1fe
--- /dev/null
+++ b/kernel/trace/ring_buffer.c
@@ -0,0 +1,2014 @@
+/*
+ * Generic ring buffer
+ *
+ * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
+ */
+#include <linux/ring_buffer.h>
+#include <linux/spinlock.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/percpu.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>	/* used for sched_clock() (for now) */
+#include <linux/init.h>
+#include <linux/hash.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+
+/* Up this if you want to test the TIME_EXTENTS and normalization */
+#define DEBUG_SHIFT 0
+
+/* FIXME!!! */
+u64 ring_buffer_time_stamp(int cpu)
+{
+	/* shift to debug/test normalization and TIME_EXTENTS */
+	return sched_clock() << DEBUG_SHIFT;
+}
+
+void ring_buffer_normalize_time_stamp(int cpu, u64 *ts)
+{
+	/* Just stupid testing the normalize function and deltas */
+	*ts >>= DEBUG_SHIFT;
+}
+
+#define RB_EVNT_HDR_SIZE (sizeof(struct ring_buffer_event))
+#define RB_ALIGNMENT_SHIFT	2
+#define RB_ALIGNMENT		(1 << RB_ALIGNMENT_SHIFT)
+#define RB_MAX_SMALL_DATA	28
+
+enum {
+	RB_LEN_TIME_EXTEND = 8,
+	RB_LEN_TIME_STAMP = 16,
+};
+
+/* inline for ring buffer fast paths */
+static inline unsigned
+rb_event_length(struct ring_buffer_event *event)
+{
+	unsigned length;
+
+	switch (event->type) {
+	case RINGBUF_TYPE_PADDING:
+		/* undefined */
+		return -1;
+
+	case RINGBUF_TYPE_TIME_EXTEND:
+		return RB_LEN_TIME_EXTEND;
+
+	case RINGBUF_TYPE_TIME_STAMP:
+		return RB_LEN_TIME_STAMP;
+
+	case RINGBUF_TYPE_DATA:
+		if (event->len)
+			length = event->len << RB_ALIGNMENT_SHIFT;
+		else
+			length = event->array[0];
+		return length + RB_EVNT_HDR_SIZE;
+	default:
+		BUG();
+	}
+	/* not hit */
+	return 0;
+}
+
+/**
+ * ring_buffer_event_length - return the length of the event
+ * @event: the event to get the length of
+ */
+unsigned ring_buffer_event_length(struct ring_buffer_event *event)
+{
+	return rb_event_length(event);
+}
+
+/* inline for ring buffer fast paths */
+static inline void *
+rb_event_data(struct ring_buffer_event *event)
+{
+	BUG_ON(event->type != RINGBUF_TYPE_DATA);
+	/* If length is in len field, then array[0] has the data */
+	if (event->len)
+		return (void *)&event->array[0];
+	/* Otherwise length is in array[0] and array[1] has the data */
+	return (void *)&event->array[1];
+}
+
+/**
+ * ring_buffer_event_data - return the data of the event
+ * @event: the event to get the data from
+ */
+void *ring_buffer_event_data(struct ring_buffer_event *event)
+{
+	return rb_event_data(event);
+}
+
+#define for_each_buffer_cpu(buffer, cpu)		\
+	for_each_cpu_mask(cpu, buffer->cpumask)
+
+#define TS_SHIFT	27
+#define TS_MASK		((1ULL << TS_SHIFT) - 1)
+#define TS_DELTA_TEST	(~TS_MASK)
+
+/*
+ * This hack stolen from mm/slob.c.
+ * We can store per page timing information in the page frame of the page.
+ * Thanks to Peter Zijlstra for suggesting this idea.
+ */
+struct buffer_page {
+	u64		 time_stamp;	/* page time stamp */
+	local_t		 write;		/* index for next write */
+	local_t		 commit;	/* write commited index */
+	unsigned	 read;		/* index for next read */
+	struct list_head list;		/* list of free pages */
+	void *page;			/* Actual data page */
+};
+
+/*
+ * Also stolen from mm/slob.c. Thanks to Mathieu Desnoyers for pointing
+ * this issue out.
+ */
+static inline void free_buffer_page(struct buffer_page *bpage)
+{
+	if (bpage->page)
+		__free_page(bpage->page);
+	kfree(bpage);
+}
+
+/*
+ * We need to fit the time_stamp delta into 27 bits.
+ */
+static inline int test_time_stamp(u64 delta)
+{
+	if (delta & TS_DELTA_TEST)
+		return 1;
+	return 0;
+}
+
+#define BUF_PAGE_SIZE PAGE_SIZE
+
+/*
+ * head_page == tail_page && head == tail then buffer is empty.
+ */
+struct ring_buffer_per_cpu {
+	int				cpu;
+	struct ring_buffer		*buffer;
+	spinlock_t			lock;
+	struct lock_class_key		lock_key;
+	struct list_head		pages;
+	struct buffer_page		*head_page;	/* read from head */
+	struct buffer_page		*tail_page;	/* write to tail */
+	struct buffer_page		*commit_page;	/* commited pages */
+	struct buffer_page		*reader_page;
+	unsigned long			overrun;
+	unsigned long			entries;
+	u64				write_stamp;
+	u64				read_stamp;
+	atomic_t			record_disabled;
+};
+
+struct ring_buffer {
+	unsigned long			size;
+	unsigned			pages;
+	unsigned			flags;
+	int				cpus;
+	cpumask_t			cpumask;
+	atomic_t			record_disabled;
+
+	struct mutex			mutex;
+
+	struct ring_buffer_per_cpu	**buffers;
+};
+
+struct ring_buffer_iter {
+	struct ring_buffer_per_cpu	*cpu_buffer;
+	unsigned long			head;
+	struct buffer_page		*head_page;
+	u64				read_stamp;
+};
+
+#define RB_WARN_ON(buffer, cond)				\
+	do {							\
+		if (unlikely(cond)) {				\
+			atomic_inc(&buffer->record_disabled);	\
+			WARN_ON(1);				\
+		}						\
+	} while (0)
+
+#define RB_WARN_ON_RET(buffer, cond)				\
+	do {							\
+		if (unlikely(cond)) {				\
+			atomic_inc(&buffer->record_disabled);	\
+			WARN_ON(1);				\
+			return -1;				\
+		}						\
+	} while (0)
+
+#define RB_WARN_ON_ONCE(buffer, cond)				\
+	do {							\
+		static int once;				\
+		if (unlikely(cond) && !once) {			\
+			once++;					\
+			atomic_inc(&buffer->record_disabled);	\
+			WARN_ON(1);				\
+		}						\
+	} while (0)
+
+/**
+ * check_pages - integrity check of buffer pages
+ * @cpu_buffer: CPU buffer with pages to test
+ *
+ * As a safty measure we check to make sure the data pages have not
+ * been corrupted.
+ */
+static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	struct list_head *head = &cpu_buffer->pages;
+	struct buffer_page *page, *tmp;
+
+	RB_WARN_ON_RET(cpu_buffer, head->next->prev != head);
+	RB_WARN_ON_RET(cpu_buffer, head->prev->next != head);
+
+	list_for_each_entry_safe(page, tmp, head, list) {
+		RB_WARN_ON_RET(cpu_buffer,
+			       page->list.next->prev != &page->list);
+		RB_WARN_ON_RET(cpu_buffer,
+			       page->list.prev->next != &page->list);
+	}
+
+	return 0;
+}
+
+static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
+			     unsigned nr_pages)
+{
+	struct list_head *head = &cpu_buffer->pages;
+	struct buffer_page *page, *tmp;
+	unsigned long addr;
+	LIST_HEAD(pages);
+	unsigned i;
+
+	for (i = 0; i < nr_pages; i++) {
+		page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()),
+				    GFP_KERNEL, cpu_to_node(cpu_buffer->cpu));
+		if (!page)
+			goto free_pages;
+		list_add(&page->list, &pages);
+
+		addr = __get_free_page(GFP_KERNEL);
+		if (!addr)
+			goto free_pages;
+		page->page = (void *)addr;
+	}
+
+	list_splice(&pages, head);
+
+	rb_check_pages(cpu_buffer);
+
+	return 0;
+
+ free_pages:
+	list_for_each_entry_safe(page, tmp, &pages, list) {
+		list_del_init(&page->list);
+		free_buffer_page(page);
+	}
+	return -ENOMEM;
+}
+
+static struct ring_buffer_per_cpu *
+rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	struct buffer_page *page;
+	unsigned long addr;
+	int ret;
+
+	cpu_buffer = kzalloc_node(ALIGN(sizeof(*cpu_buffer), cache_line_size()),
+				  GFP_KERNEL, cpu_to_node(cpu));
+	if (!cpu_buffer)
+		return NULL;
+
+	cpu_buffer->cpu = cpu;
+	cpu_buffer->buffer = buffer;
+	spin_lock_init(&cpu_buffer->lock);
+	INIT_LIST_HEAD(&cpu_buffer->pages);
+
+	page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()),
+			    GFP_KERNEL, cpu_to_node(cpu));
+	if (!page)
+		goto fail_free_buffer;
+
+	cpu_buffer->reader_page = page;
+	addr = __get_free_page(GFP_KERNEL);
+	if (!addr)
+		goto fail_free_reader;
+	page->page = (void *)addr;
+
+	INIT_LIST_HEAD(&cpu_buffer->reader_page->list);
+
+	ret = rb_allocate_pages(cpu_buffer, buffer->pages);
+	if (ret < 0)
+		goto fail_free_reader;
+
+	cpu_buffer->head_page
+		= list_entry(cpu_buffer->pages.next, struct buffer_page, list);
+	cpu_buffer->tail_page = cpu_buffer->commit_page = cpu_buffer->head_page;
+
+	return cpu_buffer;
+
+ fail_free_reader:
+	free_buffer_page(cpu_buffer->reader_page);
+
+ fail_free_buffer:
+	kfree(cpu_buffer);
+	return NULL;
+}
+
+static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	struct list_head *head = &cpu_buffer->pages;
+	struct buffer_page *page, *tmp;
+
+	list_del_init(&cpu_buffer->reader_page->list);
+	free_buffer_page(cpu_buffer->reader_page);
+
+	list_for_each_entry_safe(page, tmp, head, list) {
+		list_del_init(&page->list);
+		free_buffer_page(page);
+	}
+	kfree(cpu_buffer);
+}
+
+/*
+ * Causes compile errors if the struct buffer_page gets bigger
+ * than the struct page.
+ */
+extern int ring_buffer_page_too_big(void);
+
+/**
+ * ring_buffer_alloc - allocate a new ring_buffer
+ * @size: the size in bytes that is needed.
+ * @flags: attributes to set for the ring buffer.
+ *
+ * Currently the only flag that is available is the RB_FL_OVERWRITE
+ * flag. This flag means that the buffer will overwrite old data
+ * when the buffer wraps. If this flag is not set, the buffer will
+ * drop data when the tail hits the head.
+ */
+struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags)
+{
+	struct ring_buffer *buffer;
+	int bsize;
+	int cpu;
+
+	/* Paranoid! Optimizes out when all is well */
+	if (sizeof(struct buffer_page) > sizeof(struct page))
+		ring_buffer_page_too_big();
+
+
+	/* keep it in its own cache line */
+	buffer = kzalloc(ALIGN(sizeof(*buffer), cache_line_size()),
+			 GFP_KERNEL);
+	if (!buffer)
+		return NULL;
+
+	buffer->pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
+	buffer->flags = flags;
+
+	/* need at least two pages */
+	if (buffer->pages == 1)
+		buffer->pages++;
+
+	buffer->cpumask = cpu_possible_map;
+	buffer->cpus = nr_cpu_ids;
+
+	bsize = sizeof(void *) * nr_cpu_ids;
+	buffer->buffers = kzalloc(ALIGN(bsize, cache_line_size()),
+				  GFP_KERNEL);
+	if (!buffer->buffers)
+		goto fail_free_buffer;
+
+	for_each_buffer_cpu(buffer, cpu) {
+		buffer->buffers[cpu] =
+			rb_allocate_cpu_buffer(buffer, cpu);
+		if (!buffer->buffers[cpu])
+			goto fail_free_buffers;
+	}
+
+	mutex_init(&buffer->mutex);
+
+	return buffer;
+
+ fail_free_buffers:
+	for_each_buffer_cpu(buffer, cpu) {
+		if (buffer->buffers[cpu])
+			rb_free_cpu_buffer(buffer->buffers[cpu]);
+	}
+	kfree(buffer->buffers);
+
+ fail_free_buffer:
+	kfree(buffer);
+	return NULL;
+}
+
+/**
+ * ring_buffer_free - free a ring buffer.
+ * @buffer: the buffer to free.
+ */
+void
+ring_buffer_free(struct ring_buffer *buffer)
+{
+	int cpu;
+
+	for_each_buffer_cpu(buffer, cpu)
+		rb_free_cpu_buffer(buffer->buffers[cpu]);
+
+	kfree(buffer);
+}
+
+static void rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer);
+
+static void
+rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
+{
+	struct buffer_page *page;
+	struct list_head *p;
+	unsigned i;
+
+	atomic_inc(&cpu_buffer->record_disabled);
+	synchronize_sched();
+
+	for (i = 0; i < nr_pages; i++) {
+		BUG_ON(list_empty(&cpu_buffer->pages));
+		p = cpu_buffer->pages.next;
+		page = list_entry(p, struct buffer_page, list);
+		list_del_init(&page->list);
+		free_buffer_page(page);
+	}
+	BUG_ON(list_empty(&cpu_buffer->pages));
+
+	rb_reset_cpu(cpu_buffer);
+
+	rb_check_pages(cpu_buffer);
+
+	atomic_dec(&cpu_buffer->record_disabled);
+
+}
+
+static void
+rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
+		struct list_head *pages, unsigned nr_pages)
+{
+	struct buffer_page *page;
+	struct list_head *p;
+	unsigned i;
+
+	atomic_inc(&cpu_buffer->record_disabled);
+	synchronize_sched();
+
+	for (i = 0; i < nr_pages; i++) {
+		BUG_ON(list_empty(pages));
+		p = pages->next;
+		page = list_entry(p, struct buffer_page, list);
+		list_del_init(&page->list);
+		list_add_tail(&page->list, &cpu_buffer->pages);
+	}
+	rb_reset_cpu(cpu_buffer);
+
+	rb_check_pages(cpu_buffer);
+
+	atomic_dec(&cpu_buffer->record_disabled);
+}
+
+/**
+ * ring_buffer_resize - resize the ring buffer
+ * @buffer: the buffer to resize.
+ * @size: the new size.
+ *
+ * The tracer is responsible for making sure that the buffer is
+ * not being used while changing the size.
+ * Note: We may be able to change the above requirement by using
+ *  RCU synchronizations.
+ *
+ * Minimum size is 2 * BUF_PAGE_SIZE.
+ *
+ * Returns -1 on failure.
+ */
+int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	unsigned nr_pages, rm_pages, new_pages;
+	struct buffer_page *page, *tmp;
+	unsigned long buffer_size;
+	unsigned long addr;
+	LIST_HEAD(pages);
+	int i, cpu;
+
+	size = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
+	size *= BUF_PAGE_SIZE;
+	buffer_size = buffer->pages * BUF_PAGE_SIZE;
+
+	/* we need a minimum of two pages */
+	if (size < BUF_PAGE_SIZE * 2)
+		size = BUF_PAGE_SIZE * 2;
+
+	if (size == buffer_size)
+		return size;
+
+	mutex_lock(&buffer->mutex);
+
+	nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
+
+	if (size < buffer_size) {
+
+		/* easy case, just free pages */
+		BUG_ON(nr_pages >= buffer->pages);
+
+		rm_pages = buffer->pages - nr_pages;
+
+		for_each_buffer_cpu(buffer, cpu) {
+			cpu_buffer = buffer->buffers[cpu];
+			rb_remove_pages(cpu_buffer, rm_pages);
+		}
+		goto out;
+	}
+
+	/*
+	 * This is a bit more difficult. We only want to add pages
+	 * when we can allocate enough for all CPUs. We do this
+	 * by allocating all the pages and storing them on a local
+	 * link list. If we succeed in our allocation, then we
+	 * add these pages to the cpu_buffers. Otherwise we just free
+	 * them all and return -ENOMEM;
+	 */
+	BUG_ON(nr_pages <= buffer->pages);
+	new_pages = nr_pages - buffer->pages;
+
+	for_each_buffer_cpu(buffer, cpu) {
+		for (i = 0; i < new_pages; i++) {
+			page = kzalloc_node(ALIGN(sizeof(*page),
+						  cache_line_size()),
+					    GFP_KERNEL, cpu_to_node(cpu));
+			if (!page)
+				goto free_pages;
+			list_add(&page->list, &pages);
+			addr = __get_free_page(GFP_KERNEL);
+			if (!addr)
+				goto free_pages;
+			page->page = (void *)addr;
+		}
+	}
+
+	for_each_buffer_cpu(buffer, cpu) {
+		cpu_buffer = buffer->buffers[cpu];
+		rb_insert_pages(cpu_buffer, &pages, new_pages);
+	}
+
+	BUG_ON(!list_empty(&pages));
+
+ out:
+	buffer->pages = nr_pages;
+	mutex_unlock(&buffer->mutex);
+
+	return size;
+
+ free_pages:
+	list_for_each_entry_safe(page, tmp, &pages, list) {
+		list_del_init(&page->list);
+		free_buffer_page(page);
+	}
+	return -ENOMEM;
+}
+
+static inline int rb_null_event(struct ring_buffer_event *event)
+{
+	return event->type == RINGBUF_TYPE_PADDING;
+}
+
+static inline void *__rb_page_index(struct buffer_page *page, unsigned index)
+{
+	return page->page + index;
+}
+
+static inline struct ring_buffer_event *
+rb_reader_event(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	return __rb_page_index(cpu_buffer->reader_page,
+			       cpu_buffer->reader_page->read);
+}
+
+static inline struct ring_buffer_event *
+rb_head_event(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	return __rb_page_index(cpu_buffer->head_page,
+			       cpu_buffer->head_page->read);
+}
+
+static inline struct ring_buffer_event *
+rb_iter_head_event(struct ring_buffer_iter *iter)
+{
+	return __rb_page_index(iter->head_page, iter->head);
+}
+
+static inline unsigned rb_page_write(struct buffer_page *bpage)
+{
+	return local_read(&bpage->write);
+}
+
+static inline unsigned rb_page_commit(struct buffer_page *bpage)
+{
+	return local_read(&bpage->commit);
+}
+
+/* Size is determined by what has been commited */
+static inline unsigned rb_page_size(struct buffer_page *bpage)
+{
+	return rb_page_commit(bpage);
+}
+
+static inline unsigned
+rb_commit_index(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	return rb_page_commit(cpu_buffer->commit_page);
+}
+
+static inline unsigned rb_head_size(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	return rb_page_commit(cpu_buffer->head_page);
+}
+
+/*
+ * When the tail hits the head and the buffer is in overwrite mode,
+ * the head jumps to the next page and all content on the previous
+ * page is discarded. But before doing so, we update the overrun
+ * variable of the buffer.
+ */
+static void rb_update_overflow(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	struct ring_buffer_event *event;
+	unsigned long head;
+
+	for (head = 0; head < rb_head_size(cpu_buffer);
+	     head += rb_event_length(event)) {
+
+		event = __rb_page_index(cpu_buffer->head_page, head);
+		BUG_ON(rb_null_event(event));
+		/* Only count data entries */
+		if (event->type != RINGBUF_TYPE_DATA)
+			continue;
+		cpu_buffer->overrun++;
+		cpu_buffer->entries--;
+	}
+}
+
+static inline void rb_inc_page(struct ring_buffer_per_cpu *cpu_buffer,
+			       struct buffer_page **page)
+{
+	struct list_head *p = (*page)->list.next;
+
+	if (p == &cpu_buffer->pages)
+		p = p->next;
+
+	*page = list_entry(p, struct buffer_page, list);
+}
+
+static inline unsigned
+rb_event_index(struct ring_buffer_event *event)
+{
+	unsigned long addr = (unsigned long)event;
+
+	return (addr & ~PAGE_MASK) - (PAGE_SIZE - BUF_PAGE_SIZE);
+}
+
+static inline int
+rb_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
+	     struct ring_buffer_event *event)
+{
+	unsigned long addr = (unsigned long)event;
+	unsigned long index;
+
+	index = rb_event_index(event);
+	addr &= PAGE_MASK;
+
+	return cpu_buffer->commit_page->page == (void *)addr &&
+		rb_commit_index(cpu_buffer) == index;
+}
+
+static inline void
+rb_set_commit_event(struct ring_buffer_per_cpu *cpu_buffer,
+		    struct ring_buffer_event *event)
+{
+	unsigned long addr = (unsigned long)event;
+	unsigned long index;
+
+	index = rb_event_index(event);
+	addr &= PAGE_MASK;
+
+	while (cpu_buffer->commit_page->page != (void *)addr) {
+		RB_WARN_ON(cpu_buffer,
+			   cpu_buffer->commit_page == cpu_buffer->tail_page);
+		cpu_buffer->commit_page->commit =
+			cpu_buffer->commit_page->write;
+		rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
+		cpu_buffer->write_stamp = cpu_buffer->commit_page->time_stamp;
+	}
+
+	/* Now set the commit to the event's index */
+	local_set(&cpu_buffer->commit_page->commit, index);
+}
+
+static inline void
+rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	/*
+	 * We only race with interrupts and NMIs on this CPU.
+	 * If we own the commit event, then we can commit
+	 * all others that interrupted us, since the interruptions
+	 * are in stack format (they finish before they come
+	 * back to us). This allows us to do a simple loop to
+	 * assign the commit to the tail.
+	 */
+	while (cpu_buffer->commit_page != cpu_buffer->tail_page) {
+		cpu_buffer->commit_page->commit =
+			cpu_buffer->commit_page->write;
+		rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
+		cpu_buffer->write_stamp = cpu_buffer->commit_page->time_stamp;
+		/* add barrier to keep gcc from optimizing too much */
+		barrier();
+	}
+	while (rb_commit_index(cpu_buffer) !=
+	       rb_page_write(cpu_buffer->commit_page)) {
+		cpu_buffer->commit_page->commit =
+			cpu_buffer->commit_page->write;
+		barrier();
+	}
+}
+
+static void rb_reset_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	cpu_buffer->read_stamp = cpu_buffer->reader_page->time_stamp;
+	cpu_buffer->reader_page->read = 0;
+}
+
+static inline void rb_inc_iter(struct ring_buffer_iter *iter)
+{
+	struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
+
+	/*
+	 * The iterator could be on the reader page (it starts there).
+	 * But the head could have moved, since the reader was
+	 * found. Check for this case and assign the iterator
+	 * to the head page instead of next.
+	 */
+	if (iter->head_page == cpu_buffer->reader_page)
+		iter->head_page = cpu_buffer->head_page;
+	else
+		rb_inc_page(cpu_buffer, &iter->head_page);
+
+	iter->read_stamp = iter->head_page->time_stamp;
+	iter->head = 0;
+}
+
+/**
+ * ring_buffer_update_event - update event type and data
+ * @event: the even to update
+ * @type: the type of event
+ * @length: the size of the event field in the ring buffer
+ *
+ * Update the type and data fields of the event. The length
+ * is the actual size that is written to the ring buffer,
+ * and with this, we can determine what to place into the
+ * data field.
+ */
+static inline void
+rb_update_event(struct ring_buffer_event *event,
+			 unsigned type, unsigned length)
+{
+	event->type = type;
+
+	switch (type) {
+
+	case RINGBUF_TYPE_PADDING:
+		break;
+
+	case RINGBUF_TYPE_TIME_EXTEND:
+		event->len =
+			(RB_LEN_TIME_EXTEND + (RB_ALIGNMENT-1))
+			>> RB_ALIGNMENT_SHIFT;
+		break;
+
+	case RINGBUF_TYPE_TIME_STAMP:
+		event->len =
+			(RB_LEN_TIME_STAMP + (RB_ALIGNMENT-1))
+			>> RB_ALIGNMENT_SHIFT;
+		break;
+
+	case RINGBUF_TYPE_DATA:
+		length -= RB_EVNT_HDR_SIZE;
+		if (length > RB_MAX_SMALL_DATA) {
+			event->len = 0;
+			event->array[0] = length;
+		} else
+			event->len =
+				(length + (RB_ALIGNMENT-1))
+				>> RB_ALIGNMENT_SHIFT;
+		break;
+	default:
+		BUG();
+	}
+}
+
+static inline unsigned rb_calculate_event_length(unsigned length)
+{
+	struct ring_buffer_event event; /* Used only for sizeof array */
+
+	/* zero length can cause confusions */
+	if (!length)
+		length = 1;
+
+	if (length > RB_MAX_SMALL_DATA)
+		length += sizeof(event.array[0]);
+
+	length += RB_EVNT_HDR_SIZE;
+	length = ALIGN(length, RB_ALIGNMENT);
+
+	return length;
+}
+
+static struct ring_buffer_event *
+__rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
+		  unsigned type, unsigned long length, u64 *ts)
+{
+	struct buffer_page *tail_page, *head_page, *reader_page;
+	unsigned long tail, write;
+	struct ring_buffer *buffer = cpu_buffer->buffer;
+	struct ring_buffer_event *event;
+	unsigned long flags;
+
+	tail_page = cpu_buffer->tail_page;
+	write = local_add_return(length, &tail_page->write);
+	tail = write - length;
+
+	/* See if we shot pass the end of this buffer page */
+	if (write > BUF_PAGE_SIZE) {
+		struct buffer_page *next_page = tail_page;
+
+		spin_lock_irqsave(&cpu_buffer->lock, flags);
+
+		rb_inc_page(cpu_buffer, &next_page);
+
+		head_page = cpu_buffer->head_page;
+		reader_page = cpu_buffer->reader_page;
+
+		/* we grabbed the lock before incrementing */
+		RB_WARN_ON(cpu_buffer, next_page == reader_page);
+
+		/*
+		 * If for some reason, we had an interrupt storm that made
+		 * it all the way around the buffer, bail, and warn
+		 * about it.
+		 */
+		if (unlikely(next_page == cpu_buffer->commit_page)) {
+			WARN_ON_ONCE(1);
+			goto out_unlock;
+		}
+
+		if (next_page == head_page) {
+			if (!(buffer->flags & RB_FL_OVERWRITE)) {
+				/* reset write */
+				if (tail <= BUF_PAGE_SIZE)
+					local_set(&tail_page->write, tail);
+				goto out_unlock;
+			}
+
+			/* tail_page has not moved yet? */
+			if (tail_page == cpu_buffer->tail_page) {
+				/* count overflows */
+				rb_update_overflow(cpu_buffer);
+
+				rb_inc_page(cpu_buffer, &head_page);
+				cpu_buffer->head_page = head_page;
+				cpu_buffer->head_page->read = 0;
+			}
+		}
+
+		/*
+		 * If the tail page is still the same as what we think
+		 * it is, then it is up to us to update the tail
+		 * pointer.
+		 */
+		if (tail_page == cpu_buffer->tail_page) {
+			local_set(&next_page->write, 0);
+			local_set(&next_page->commit, 0);
+			cpu_buffer->tail_page = next_page;
+
+			/* reread the time stamp */
+			*ts = ring_buffer_time_stamp(cpu_buffer->cpu);
+			cpu_buffer->tail_page->time_stamp = *ts;
+		}
+
+		/*
+		 * The actual tail page has moved forward.
+		 */
+		if (tail < BUF_PAGE_SIZE) {
+			/* Mark the rest of the page with padding */
+			event = __rb_page_index(tail_page, tail);
+			event->type = RINGBUF_TYPE_PADDING;
+		}
+
+		if (tail <= BUF_PAGE_SIZE)
+			/* Set the write back to the previous setting */
+			local_set(&tail_page->write, tail);
+
+		/*
+		 * If this was a commit entry that failed,
+		 * increment that too
+		 */
+		if (tail_page == cpu_buffer->commit_page &&
+		    tail == rb_commit_index(cpu_buffer)) {
+			rb_set_commit_to_write(cpu_buffer);
+		}
+
+		spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+
+		/* fail and let the caller try again */
+		return ERR_PTR(-EAGAIN);
+	}
+
+	/* We reserved something on the buffer */
+
+	BUG_ON(write > BUF_PAGE_SIZE);
+
+	event = __rb_page_index(tail_page, tail);
+	rb_update_event(event, type, length);
+
+	/*
+	 * If this is a commit and the tail is zero, then update
+	 * this page's time stamp.
+	 */
+	if (!tail && rb_is_commit(cpu_buffer, event))
+		cpu_buffer->commit_page->time_stamp = *ts;
+
+	return event;
+
+ out_unlock:
+	spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+	return NULL;
+}
+
+static int
+rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer,
+		  u64 *ts, u64 *delta)
+{
+	struct ring_buffer_event *event;
+	static int once;
+	int ret;
+
+	if (unlikely(*delta > (1ULL << 59) && !once++)) {
+		printk(KERN_WARNING "Delta way too big! %llu"
+		       " ts=%llu write stamp = %llu\n",
+		       *delta, *ts, cpu_buffer->write_stamp);
+		WARN_ON(1);
+	}
+
+	/*
+	 * The delta is too big, we to add a
+	 * new timestamp.
+	 */
+	event = __rb_reserve_next(cpu_buffer,
+				  RINGBUF_TYPE_TIME_EXTEND,
+				  RB_LEN_TIME_EXTEND,
+				  ts);
+	if (!event)
+		return -EBUSY;
+
+	if (PTR_ERR(event) == -EAGAIN)
+		return -EAGAIN;
+
+	/* Only a commited time event can update the write stamp */
+	if (rb_is_commit(cpu_buffer, event)) {
+		/*
+		 * If this is the first on the page, then we need to
+		 * update the page itself, and just put in a zero.
+		 */
+		if (rb_event_index(event)) {
+			event->time_delta = *delta & TS_MASK;
+			event->array[0] = *delta >> TS_SHIFT;
+		} else {
+			cpu_buffer->commit_page->time_stamp = *ts;
+			event->time_delta = 0;
+			event->array[0] = 0;
+		}
+		cpu_buffer->write_stamp = *ts;
+		/* let the caller know this was the commit */
+		ret = 1;
+	} else {
+		/* Darn, this is just wasted space */
+		event->time_delta = 0;
+		event->array[0] = 0;
+		ret = 0;
+	}
+
+	*delta = 0;
+
+	return ret;
+}
+
+static struct ring_buffer_event *
+rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer,
+		      unsigned type, unsigned long length)
+{
+	struct ring_buffer_event *event;
+	u64 ts, delta;
+	int commit = 0;
+
+ again:
+	ts = ring_buffer_time_stamp(cpu_buffer->cpu);
+
+	/*
+	 * Only the first commit can update the timestamp.
+	 * Yes there is a race here. If an interrupt comes in
+	 * just after the conditional and it traces too, then it
+	 * will also check the deltas. More than one timestamp may
+	 * also be made. But only the entry that did the actual
+	 * commit will be something other than zero.
+	 */
+	if (cpu_buffer->tail_page == cpu_buffer->commit_page &&
+	    rb_page_write(cpu_buffer->tail_page) ==
+	    rb_commit_index(cpu_buffer)) {
+
+		delta = ts - cpu_buffer->write_stamp;
+
+		/* make sure this delta is calculated here */
+		barrier();
+
+		/* Did the write stamp get updated already? */
+		if (unlikely(ts < cpu_buffer->write_stamp))
+			goto again;
+
+		if (test_time_stamp(delta)) {
+
+			commit = rb_add_time_stamp(cpu_buffer, &ts, &delta);
+
+			if (commit == -EBUSY)
+				return NULL;
+
+			if (commit == -EAGAIN)
+				goto again;
+
+			RB_WARN_ON(cpu_buffer, commit < 0);
+		}
+	} else
+		/* Non commits have zero deltas */
+		delta = 0;
+
+	event = __rb_reserve_next(cpu_buffer, type, length, &ts);
+	if (PTR_ERR(event) == -EAGAIN)
+		goto again;
+
+	if (!event) {
+		if (unlikely(commit))
+			/*
+			 * Ouch! We needed a timestamp and it was commited. But
+			 * we didn't get our event reserved.
+			 */
+			rb_set_commit_to_write(cpu_buffer);
+		return NULL;
+	}
+
+	/*
+	 * If the timestamp was commited, make the commit our entry
+	 * now so that we will update it when needed.
+	 */
+	if (commit)
+		rb_set_commit_event(cpu_buffer, event);
+	else if (!rb_is_commit(cpu_buffer, event))
+		delta = 0;
+
+	event->time_delta = delta;
+
+	return event;
+}
+
+static DEFINE_PER_CPU(int, rb_need_resched);
+
+/**
+ * ring_buffer_lock_reserve - reserve a part of the buffer
+ * @buffer: the ring buffer to reserve from
+ * @length: the length of the data to reserve (excluding event header)
+ * @flags: a pointer to save the interrupt flags
+ *
+ * Returns a reseverd event on the ring buffer to copy directly to.
+ * The user of this interface will need to get the body to write into
+ * and can use the ring_buffer_event_data() interface.
+ *
+ * The length is the length of the data needed, not the event length
+ * which also includes the event header.
+ *
+ * Must be paired with ring_buffer_unlock_commit, unless NULL is returned.
+ * If NULL is returned, then nothing has been allocated or locked.
+ */
+struct ring_buffer_event *
+ring_buffer_lock_reserve(struct ring_buffer *buffer,
+			 unsigned long length,
+			 unsigned long *flags)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	struct ring_buffer_event *event;
+	int cpu, resched;
+
+	if (atomic_read(&buffer->record_disabled))
+		return NULL;
+
+	/* If we are tracing schedule, we don't want to recurse */
+	resched = need_resched();
+	preempt_disable_notrace();
+
+	cpu = raw_smp_processor_id();
+
+	if (!cpu_isset(cpu, buffer->cpumask))
+		goto out;
+
+	cpu_buffer = buffer->buffers[cpu];
+
+	if (atomic_read(&cpu_buffer->record_disabled))
+		goto out;
+
+	length = rb_calculate_event_length(length);
+	if (length > BUF_PAGE_SIZE)
+		goto out;
+
+	event = rb_reserve_next_event(cpu_buffer, RINGBUF_TYPE_DATA, length);
+	if (!event)
+		goto out;
+
+	/*
+	 * Need to store resched state on this cpu.
+	 * Only the first needs to.
+	 */
+
+	if (preempt_count() == 1)
+		per_cpu(rb_need_resched, cpu) = resched;
+
+	return event;
+
+ out:
+	if (resched)
+		preempt_enable_notrace();
+	else
+		preempt_enable_notrace();
+	return NULL;
+}
+
+static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
+		      struct ring_buffer_event *event)
+{
+	cpu_buffer->entries++;
+
+	/* Only process further if we own the commit */
+	if (!rb_is_commit(cpu_buffer, event))
+		return;
+
+	cpu_buffer->write_stamp += event->time_delta;
+
+	rb_set_commit_to_write(cpu_buffer);
+}
+
+/**
+ * ring_buffer_unlock_commit - commit a reserved
+ * @buffer: The buffer to commit to
+ * @event: The event pointer to commit.
+ * @flags: the interrupt flags received from ring_buffer_lock_reserve.
+ *
+ * This commits the data to the ring buffer, and releases any locks held.
+ *
+ * Must be paired with ring_buffer_lock_reserve.
+ */
+int ring_buffer_unlock_commit(struct ring_buffer *buffer,
+			      struct ring_buffer_event *event,
+			      unsigned long flags)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	int cpu = raw_smp_processor_id();
+
+	cpu_buffer = buffer->buffers[cpu];
+
+	rb_commit(cpu_buffer, event);
+
+	/*
+	 * Only the last preempt count needs to restore preemption.
+	 */
+	if (preempt_count() == 1) {
+		if (per_cpu(rb_need_resched, cpu))
+			preempt_enable_no_resched_notrace();
+		else
+			preempt_enable_notrace();
+	} else
+		preempt_enable_no_resched_notrace();
+
+	return 0;
+}
+
+/**
+ * ring_buffer_write - write data to the buffer without reserving
+ * @buffer: The ring buffer to write to.
+ * @length: The length of the data being written (excluding the event header)
+ * @data: The data to write to the buffer.
+ *
+ * This is like ring_buffer_lock_reserve and ring_buffer_unlock_commit as
+ * one function. If you already have the data to write to the buffer, it
+ * may be easier to simply call this function.
+ *
+ * Note, like ring_buffer_lock_reserve, the length is the length of the data
+ * and not the length of the event which would hold the header.
+ */
+int ring_buffer_write(struct ring_buffer *buffer,
+			unsigned long length,
+			void *data)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	struct ring_buffer_event *event;
+	unsigned long event_length;
+	void *body;
+	int ret = -EBUSY;
+	int cpu, resched;
+
+	if (atomic_read(&buffer->record_disabled))
+		return -EBUSY;
+
+	resched = need_resched();
+	preempt_disable_notrace();
+
+	cpu = raw_smp_processor_id();
+
+	if (!cpu_isset(cpu, buffer->cpumask))
+		goto out;
+
+	cpu_buffer = buffer->buffers[cpu];
+
+	if (atomic_read(&cpu_buffer->record_disabled))
+		goto out;
+
+	event_length = rb_calculate_event_length(length);
+	event = rb_reserve_next_event(cpu_buffer,
+				      RINGBUF_TYPE_DATA, event_length);
+	if (!event)
+		goto out;
+
+	body = rb_event_data(event);
+
+	memcpy(body, data, length);
+
+	rb_commit(cpu_buffer, event);
+
+	ret = 0;
+ out:
+	if (resched)
+		preempt_enable_no_resched_notrace();
+	else
+		preempt_enable_notrace();
+
+	return ret;
+}
+
+static inline int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	struct buffer_page *reader = cpu_buffer->reader_page;
+	struct buffer_page *head = cpu_buffer->head_page;
+	struct buffer_page *commit = cpu_buffer->commit_page;
+
+	return reader->read == rb_page_commit(reader) &&
+		(commit == reader ||
+		 (commit == head &&
+		  head->read == rb_page_commit(commit)));
+}
+
+/**
+ * ring_buffer_record_disable - stop all writes into the buffer
+ * @buffer: The ring buffer to stop writes to.
+ *
+ * This prevents all writes to the buffer. Any attempt to write
+ * to the buffer after this will fail and return NULL.
+ *
+ * The caller should call synchronize_sched() after this.
+ */
+void ring_buffer_record_disable(struct ring_buffer *buffer)
+{
+	atomic_inc(&buffer->record_disabled);
+}
+
+/**
+ * ring_buffer_record_enable - enable writes to the buffer
+ * @buffer: The ring buffer to enable writes
+ *
+ * Note, multiple disables will need the same number of enables
+ * to truely enable the writing (much like preempt_disable).
+ */
+void ring_buffer_record_enable(struct ring_buffer *buffer)
+{
+	atomic_dec(&buffer->record_disabled);
+}
+
+/**
+ * ring_buffer_record_disable_cpu - stop all writes into the cpu_buffer
+ * @buffer: The ring buffer to stop writes to.
+ * @cpu: The CPU buffer to stop
+ *
+ * This prevents all writes to the buffer. Any attempt to write
+ * to the buffer after this will fail and return NULL.
+ *
+ * The caller should call synchronize_sched() after this.
+ */
+void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+
+	if (!cpu_isset(cpu, buffer->cpumask))
+		return;
+
+	cpu_buffer = buffer->buffers[cpu];
+	atomic_inc(&cpu_buffer->record_disabled);
+}
+
+/**
+ * ring_buffer_record_enable_cpu - enable writes to the buffer
+ * @buffer: The ring buffer to enable writes
+ * @cpu: The CPU to enable.
+ *
+ * Note, multiple disables will need the same number of enables
+ * to truely enable the writing (much like preempt_disable).
+ */
+void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+
+	if (!cpu_isset(cpu, buffer->cpumask))
+		return;
+
+	cpu_buffer = buffer->buffers[cpu];
+	atomic_dec(&cpu_buffer->record_disabled);
+}
+
+/**
+ * ring_buffer_entries_cpu - get the number of entries in a cpu buffer
+ * @buffer: The ring buffer
+ * @cpu: The per CPU buffer to get the entries from.
+ */
+unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+
+	if (!cpu_isset(cpu, buffer->cpumask))
+		return 0;
+
+	cpu_buffer = buffer->buffers[cpu];
+	return cpu_buffer->entries;
+}
+
+/**
+ * ring_buffer_overrun_cpu - get the number of overruns in a cpu_buffer
+ * @buffer: The ring buffer
+ * @cpu: The per CPU buffer to get the number of overruns from
+ */
+unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+
+	if (!cpu_isset(cpu, buffer->cpumask))
+		return 0;
+
+	cpu_buffer = buffer->buffers[cpu];
+	return cpu_buffer->overrun;
+}
+
+/**
+ * ring_buffer_entries - get the number of entries in a buffer
+ * @buffer: The ring buffer
+ *
+ * Returns the total number of entries in the ring buffer
+ * (all CPU entries)
+ */
+unsigned long ring_buffer_entries(struct ring_buffer *buffer)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	unsigned long entries = 0;
+	int cpu;
+
+	/* if you care about this being correct, lock the buffer */
+	for_each_buffer_cpu(buffer, cpu) {
+		cpu_buffer = buffer->buffers[cpu];
+		entries += cpu_buffer->entries;
+	}
+
+	return entries;
+}
+
+/**
+ * ring_buffer_overrun_cpu - get the number of overruns in buffer
+ * @buffer: The ring buffer
+ *
+ * Returns the total number of overruns in the ring buffer
+ * (all CPU entries)
+ */
+unsigned long ring_buffer_overruns(struct ring_buffer *buffer)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	unsigned long overruns = 0;
+	int cpu;
+
+	/* if you care about this being correct, lock the buffer */
+	for_each_buffer_cpu(buffer, cpu) {
+		cpu_buffer = buffer->buffers[cpu];
+		overruns += cpu_buffer->overrun;
+	}
+
+	return overruns;
+}
+
+/**
+ * ring_buffer_iter_reset - reset an iterator
+ * @iter: The iterator to reset
+ *
+ * Resets the iterator, so that it will start from the beginning
+ * again.
+ */
+void ring_buffer_iter_reset(struct ring_buffer_iter *iter)
+{
+	struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
+
+	/* Iterator usage is expected to have record disabled */
+	if (list_empty(&cpu_buffer->reader_page->list)) {
+		iter->head_page = cpu_buffer->head_page;
+		iter->head = cpu_buffer->head_page->read;
+	} else {
+		iter->head_page = cpu_buffer->reader_page;
+		iter->head = cpu_buffer->reader_page->read;
+	}
+	if (iter->head)
+		iter->read_stamp = cpu_buffer->read_stamp;
+	else
+		iter->read_stamp = iter->head_page->time_stamp;
+}
+
+/**
+ * ring_buffer_iter_empty - check if an iterator has no more to read
+ * @iter: The iterator to check
+ */
+int ring_buffer_iter_empty(struct ring_buffer_iter *iter)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+
+	cpu_buffer = iter->cpu_buffer;
+
+	return iter->head_page == cpu_buffer->commit_page &&
+		iter->head == rb_commit_index(cpu_buffer);
+}
+
+static void
+rb_update_read_stamp(struct ring_buffer_per_cpu *cpu_buffer,
+		     struct ring_buffer_event *event)
+{
+	u64 delta;
+
+	switch (event->type) {
+	case RINGBUF_TYPE_PADDING:
+		return;
+
+	case RINGBUF_TYPE_TIME_EXTEND:
+		delta = event->array[0];
+		delta <<= TS_SHIFT;
+		delta += event->time_delta;
+		cpu_buffer->read_stamp += delta;
+		return;
+
+	case RINGBUF_TYPE_TIME_STAMP:
+		/* FIXME: not implemented */
+		return;
+
+	case RINGBUF_TYPE_DATA:
+		cpu_buffer->read_stamp += event->time_delta;
+		return;
+
+	default:
+		BUG();
+	}
+	return;
+}
+
+static void
+rb_update_iter_read_stamp(struct ring_buffer_iter *iter,
+			  struct ring_buffer_event *event)
+{
+	u64 delta;
+
+	switch (event->type) {
+	case RINGBUF_TYPE_PADDING:
+		return;
+
+	case RINGBUF_TYPE_TIME_EXTEND:
+		delta = event->array[0];
+		delta <<= TS_SHIFT;
+		delta += event->time_delta;
+		iter->read_stamp += delta;
+		return;
+
+	case RINGBUF_TYPE_TIME_STAMP:
+		/* FIXME: not implemented */
+		return;
+
+	case RINGBUF_TYPE_DATA:
+		iter->read_stamp += event->time_delta;
+		return;
+
+	default:
+		BUG();
+	}
+	return;
+}
+
+static struct buffer_page *
+rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	struct buffer_page *reader = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cpu_buffer->lock, flags);
+
+ again:
+	reader = cpu_buffer->reader_page;
+
+	/* If there's more to read, return this page */
+	if (cpu_buffer->reader_page->read < rb_page_size(reader))
+		goto out;
+
+	/* Never should we have an index greater than the size */
+	RB_WARN_ON(cpu_buffer,
+		   cpu_buffer->reader_page->read > rb_page_size(reader));
+
+	/* check if we caught up to the tail */
+	reader = NULL;
+	if (cpu_buffer->commit_page == cpu_buffer->reader_page)
+		goto out;
+
+	/*
+	 * Splice the empty reader page into the list around the head.
+	 * Reset the reader page to size zero.
+	 */
+
+	reader = cpu_buffer->head_page;
+	cpu_buffer->reader_page->list.next = reader->list.next;
+	cpu_buffer->reader_page->list.prev = reader->list.prev;
+
+	local_set(&cpu_buffer->reader_page->write, 0);
+	local_set(&cpu_buffer->reader_page->commit, 0);
+
+	/* Make the reader page now replace the head */
+	reader->list.prev->next = &cpu_buffer->reader_page->list;
+	reader->list.next->prev = &cpu_buffer->reader_page->list;
+
+	/*
+	 * If the tail is on the reader, then we must set the head
+	 * to the inserted page, otherwise we set it one before.
+	 */
+	cpu_buffer->head_page = cpu_buffer->reader_page;
+
+	if (cpu_buffer->commit_page != reader)
+		rb_inc_page(cpu_buffer, &cpu_buffer->head_page);
+
+	/* Finally update the reader page to the new head */
+	cpu_buffer->reader_page = reader;
+	rb_reset_reader_page(cpu_buffer);
+
+	goto again;
+
+ out:
+	spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+
+	return reader;
+}
+
+static void rb_advance_reader(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	struct ring_buffer_event *event;
+	struct buffer_page *reader;
+	unsigned length;
+
+	reader = rb_get_reader_page(cpu_buffer);
+
+	/* This function should not be called when buffer is empty */
+	BUG_ON(!reader);
+
+	event = rb_reader_event(cpu_buffer);
+
+	if (event->type == RINGBUF_TYPE_DATA)
+		cpu_buffer->entries--;
+
+	rb_update_read_stamp(cpu_buffer, event);
+
+	length = rb_event_length(event);
+	cpu_buffer->reader_page->read += length;
+}
+
+static void rb_advance_iter(struct ring_buffer_iter *iter)
+{
+	struct ring_buffer *buffer;
+	struct ring_buffer_per_cpu *cpu_buffer;
+	struct ring_buffer_event *event;
+	unsigned length;
+
+	cpu_buffer = iter->cpu_buffer;
+	buffer = cpu_buffer->buffer;
+
+	/*
+	 * Check if we are at the end of the buffer.
+	 */
+	if (iter->head >= rb_page_size(iter->head_page)) {
+		BUG_ON(iter->head_page == cpu_buffer->commit_page);
+		rb_inc_iter(iter);
+		return;
+	}
+
+	event = rb_iter_head_event(iter);
+
+	length = rb_event_length(event);
+
+	/*
+	 * This should not be called to advance the header if we are
+	 * at the tail of the buffer.
+	 */
+	BUG_ON((iter->head_page == cpu_buffer->commit_page) &&
+	       (iter->head + length > rb_commit_index(cpu_buffer)));
+
+	rb_update_iter_read_stamp(iter, event);
+
+	iter->head += length;
+
+	/* check for end of page padding */
+	if ((iter->head >= rb_page_size(iter->head_page)) &&
+	    (iter->head_page != cpu_buffer->commit_page))
+		rb_advance_iter(iter);
+}
+
+/**
+ * ring_buffer_peek - peek at the next event to be read
+ * @buffer: The ring buffer to read
+ * @cpu: The cpu to peak at
+ * @ts: The timestamp counter of this event.
+ *
+ * This will return the event that will be read next, but does
+ * not consume the data.
+ */
+struct ring_buffer_event *
+ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	struct ring_buffer_event *event;
+	struct buffer_page *reader;
+
+	if (!cpu_isset(cpu, buffer->cpumask))
+		return NULL;
+
+	cpu_buffer = buffer->buffers[cpu];
+
+ again:
+	reader = rb_get_reader_page(cpu_buffer);
+	if (!reader)
+		return NULL;
+
+	event = rb_reader_event(cpu_buffer);
+
+	switch (event->type) {
+	case RINGBUF_TYPE_PADDING:
+		RB_WARN_ON(cpu_buffer, 1);
+		rb_advance_reader(cpu_buffer);
+		return NULL;
+
+	case RINGBUF_TYPE_TIME_EXTEND:
+		/* Internal data, OK to advance */
+		rb_advance_reader(cpu_buffer);
+		goto again;
+
+	case RINGBUF_TYPE_TIME_STAMP:
+		/* FIXME: not implemented */
+		rb_advance_reader(cpu_buffer);
+		goto again;
+
+	case RINGBUF_TYPE_DATA:
+		if (ts) {
+			*ts = cpu_buffer->read_stamp + event->time_delta;
+			ring_buffer_normalize_time_stamp(cpu_buffer->cpu, ts);
+		}
+		return event;
+
+	default:
+		BUG();
+	}
+
+	return NULL;
+}
+
+/**
+ * ring_buffer_iter_peek - peek at the next event to be read
+ * @iter: The ring buffer iterator
+ * @ts: The timestamp counter of this event.
+ *
+ * This will return the event that will be read next, but does
+ * not increment the iterator.
+ */
+struct ring_buffer_event *
+ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
+{
+	struct ring_buffer *buffer;
+	struct ring_buffer_per_cpu *cpu_buffer;
+	struct ring_buffer_event *event;
+
+	if (ring_buffer_iter_empty(iter))
+		return NULL;
+
+	cpu_buffer = iter->cpu_buffer;
+	buffer = cpu_buffer->buffer;
+
+ again:
+	if (rb_per_cpu_empty(cpu_buffer))
+		return NULL;
+
+	event = rb_iter_head_event(iter);
+
+	switch (event->type) {
+	case RINGBUF_TYPE_PADDING:
+		rb_inc_iter(iter);
+		goto again;
+
+	case RINGBUF_TYPE_TIME_EXTEND:
+		/* Internal data, OK to advance */
+		rb_advance_iter(iter);
+		goto again;
+
+	case RINGBUF_TYPE_TIME_STAMP:
+		/* FIXME: not implemented */
+		rb_advance_iter(iter);
+		goto again;
+
+	case RINGBUF_TYPE_DATA:
+		if (ts) {
+			*ts = iter->read_stamp + event->time_delta;
+			ring_buffer_normalize_time_stamp(cpu_buffer->cpu, ts);
+		}
+		return event;
+
+	default:
+		BUG();
+	}
+
+	return NULL;
+}
+
+/**
+ * ring_buffer_consume - return an event and consume it
+ * @buffer: The ring buffer to get the next event from
+ *
+ * Returns the next event in the ring buffer, and that event is consumed.
+ * Meaning, that sequential reads will keep returning a different event,
+ * and eventually empty the ring buffer if the producer is slower.
+ */
+struct ring_buffer_event *
+ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	struct ring_buffer_event *event;
+
+	if (!cpu_isset(cpu, buffer->cpumask))
+		return NULL;
+
+	event = ring_buffer_peek(buffer, cpu, ts);
+	if (!event)
+		return NULL;
+
+	cpu_buffer = buffer->buffers[cpu];
+	rb_advance_reader(cpu_buffer);
+
+	return event;
+}
+
+/**
+ * ring_buffer_read_start - start a non consuming read of the buffer
+ * @buffer: The ring buffer to read from
+ * @cpu: The cpu buffer to iterate over
+ *
+ * This starts up an iteration through the buffer. It also disables
+ * the recording to the buffer until the reading is finished.
+ * This prevents the reading from being corrupted. This is not
+ * a consuming read, so a producer is not expected.
+ *
+ * Must be paired with ring_buffer_finish.
+ */
+struct ring_buffer_iter *
+ring_buffer_read_start(struct ring_buffer *buffer, int cpu)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	struct ring_buffer_iter *iter;
+	unsigned long flags;
+
+	if (!cpu_isset(cpu, buffer->cpumask))
+		return NULL;
+
+	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+	if (!iter)
+		return NULL;
+
+	cpu_buffer = buffer->buffers[cpu];
+
+	iter->cpu_buffer = cpu_buffer;
+
+	atomic_inc(&cpu_buffer->record_disabled);
+	synchronize_sched();
+
+	spin_lock_irqsave(&cpu_buffer->lock, flags);
+	ring_buffer_iter_reset(iter);
+	spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+
+	return iter;
+}
+
+/**
+ * ring_buffer_finish - finish reading the iterator of the buffer
+ * @iter: The iterator retrieved by ring_buffer_start
+ *
+ * This re-enables the recording to the buffer, and frees the
+ * iterator.
+ */
+void
+ring_buffer_read_finish(struct ring_buffer_iter *iter)
+{
+	struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
+
+	atomic_dec(&cpu_buffer->record_disabled);
+	kfree(iter);
+}
+
+/**
+ * ring_buffer_read - read the next item in the ring buffer by the iterator
+ * @iter: The ring buffer iterator
+ * @ts: The time stamp of the event read.
+ *
+ * This reads the next event in the ring buffer and increments the iterator.
+ */
+struct ring_buffer_event *
+ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts)
+{
+	struct ring_buffer_event *event;
+
+	event = ring_buffer_iter_peek(iter, ts);
+	if (!event)
+		return NULL;
+
+	rb_advance_iter(iter);
+
+	return event;
+}
+
+/**
+ * ring_buffer_size - return the size of the ring buffer (in bytes)
+ * @buffer: The ring buffer.
+ */
+unsigned long ring_buffer_size(struct ring_buffer *buffer)
+{
+	return BUF_PAGE_SIZE * buffer->pages;
+}
+
+static void
+rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
+{
+	cpu_buffer->head_page
+		= list_entry(cpu_buffer->pages.next, struct buffer_page, list);
+	local_set(&cpu_buffer->head_page->write, 0);
+	local_set(&cpu_buffer->head_page->commit, 0);
+
+	cpu_buffer->head_page->read = 0;
+
+	cpu_buffer->tail_page = cpu_buffer->head_page;
+	cpu_buffer->commit_page = cpu_buffer->head_page;
+
+	INIT_LIST_HEAD(&cpu_buffer->reader_page->list);
+	local_set(&cpu_buffer->reader_page->write, 0);
+	local_set(&cpu_buffer->reader_page->commit, 0);
+	cpu_buffer->reader_page->read = 0;
+
+	cpu_buffer->overrun = 0;
+	cpu_buffer->entries = 0;
+}
+
+/**
+ * ring_buffer_reset_cpu - reset a ring buffer per CPU buffer
+ * @buffer: The ring buffer to reset a per cpu buffer of
+ * @cpu: The CPU buffer to be reset
+ */
+void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)
+{
+	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+	unsigned long flags;
+
+	if (!cpu_isset(cpu, buffer->cpumask))
+		return;
+
+	spin_lock_irqsave(&cpu_buffer->lock, flags);
+
+	rb_reset_cpu(cpu_buffer);
+
+	spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+}
+
+/**
+ * ring_buffer_reset - reset a ring buffer
+ * @buffer: The ring buffer to reset all cpu buffers
+ */
+void ring_buffer_reset(struct ring_buffer *buffer)
+{
+	int cpu;
+
+	for_each_buffer_cpu(buffer, cpu)
+		ring_buffer_reset_cpu(buffer, cpu);
+}
+
+/**
+ * rind_buffer_empty - is the ring buffer empty?
+ * @buffer: The ring buffer to test
+ */
+int ring_buffer_empty(struct ring_buffer *buffer)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+	int cpu;
+
+	/* yes this is racy, but if you don't like the race, lock the buffer */
+	for_each_buffer_cpu(buffer, cpu) {
+		cpu_buffer = buffer->buffers[cpu];
+		if (!rb_per_cpu_empty(cpu_buffer))
+			return 0;
+	}
+	return 1;
+}
+
+/**
+ * ring_buffer_empty_cpu - is a cpu buffer of a ring buffer empty?
+ * @buffer: The ring buffer
+ * @cpu: The CPU buffer to test
+ */
+int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu)
+{
+	struct ring_buffer_per_cpu *cpu_buffer;
+
+	if (!cpu_isset(cpu, buffer->cpumask))
+		return 1;
+
+	cpu_buffer = buffer->buffers[cpu];
+	return rb_per_cpu_empty(cpu_buffer);
+}
+
+/**
+ * ring_buffer_swap_cpu - swap a CPU buffer between two ring buffers
+ * @buffer_a: One buffer to swap with
+ * @buffer_b: The other buffer to swap with
+ *
+ * This function is useful for tracers that want to take a "snapshot"
+ * of a CPU buffer and has another back up buffer lying around.
+ * it is expected that the tracer handles the cpu buffer not being
+ * used at the moment.
+ */
+int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
+			 struct ring_buffer *buffer_b, int cpu)
+{
+	struct ring_buffer_per_cpu *cpu_buffer_a;
+	struct ring_buffer_per_cpu *cpu_buffer_b;
+
+	if (!cpu_isset(cpu, buffer_a->cpumask) ||
+	    !cpu_isset(cpu, buffer_b->cpumask))
+		return -EINVAL;
+
+	/* At least make sure the two buffers are somewhat the same */
+	if (buffer_a->size != buffer_b->size ||
+	    buffer_a->pages != buffer_b->pages)
+		return -EINVAL;
+
+	cpu_buffer_a = buffer_a->buffers[cpu];
+	cpu_buffer_b = buffer_b->buffers[cpu];
+
+	/*
+	 * We can't do a synchronize_sched here because this
+	 * function can be called in atomic context.
+	 * Normally this will be called from the same CPU as cpu.
+	 * If not it's up to the caller to protect this.
+	 */
+	atomic_inc(&cpu_buffer_a->record_disabled);
+	atomic_inc(&cpu_buffer_b->record_disabled);
+
+	buffer_a->buffers[cpu] = cpu_buffer_b;
+	buffer_b->buffers[cpu] = cpu_buffer_a;
+
+	cpu_buffer_b->buffer = buffer_a;
+	cpu_buffer_a->buffer = buffer_b;
+
+	atomic_dec(&cpu_buffer_a->record_disabled);
+	atomic_dec(&cpu_buffer_b->record_disabled);
+
+	return 0;
+}
+
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8f3fb3d..d345d64 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -14,6 +14,7 @@
 #include <linux/utsrelease.h>
 #include <linux/kallsyms.h>
 #include <linux/seq_file.h>
+#include <linux/notifier.h>
 #include <linux/debugfs.h>
 #include <linux/pagemap.h>
 #include <linux/hardirq.h>
@@ -22,6 +23,7 @@
 #include <linux/ftrace.h>
 #include <linux/module.h>
 #include <linux/percpu.h>
+#include <linux/kdebug.h>
 #include <linux/ctype.h>
 #include <linux/init.h>
 #include <linux/poll.h>
@@ -31,25 +33,36 @@
 #include <linux/writeback.h>
 
 #include <linux/stacktrace.h>
+#include <linux/ring_buffer.h>
 
 #include "trace.h"
 
+#define TRACE_BUFFER_FLAGS	(RB_FL_OVERWRITE)
+
 unsigned long __read_mostly	tracing_max_latency = (cycle_t)ULONG_MAX;
 unsigned long __read_mostly	tracing_thresh;
 
-static unsigned long __read_mostly	tracing_nr_buffers;
+static DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);
+
+static inline void ftrace_disable_cpu(void)
+{
+	preempt_disable();
+	local_inc(&__get_cpu_var(ftrace_cpu_disabled));
+}
+
+static inline void ftrace_enable_cpu(void)
+{
+	local_dec(&__get_cpu_var(ftrace_cpu_disabled));
+	preempt_enable();
+}
+
 static cpumask_t __read_mostly		tracing_buffer_mask;
 
 #define for_each_tracing_cpu(cpu)	\
 	for_each_cpu_mask(cpu, tracing_buffer_mask)
 
-static int trace_alloc_page(void);
-static int trace_free_page(void);
-
 static int tracing_disabled = 1;
 
-static unsigned long tracing_pages_allocated;
-
 long
 ns2usecs(cycle_t nsec)
 {
@@ -60,7 +73,9 @@ ns2usecs(cycle_t nsec)
 
 cycle_t ftrace_now(int cpu)
 {
-	return cpu_clock(cpu);
+	u64 ts = ring_buffer_time_stamp(cpu);
+	ring_buffer_normalize_time_stamp(cpu, &ts);
+	return ts;
 }
 
 /*
@@ -100,11 +115,18 @@ static int			tracer_enabled = 1;
 int				ftrace_function_enabled;
 
 /*
- * trace_nr_entries is the number of entries that is allocated
- * for a buffer. Note, the number of entries is always rounded
- * to ENTRIES_PER_PAGE.
+ * trace_buf_size is the size in bytes that is allocated
+ * for a buffer. Note, the number of bytes is always rounded
+ * to page size.
+ *
+ * This number is purposely set to a low number of 16384.
+ * If the dump on oops happens, it will be much appreciated
+ * to not have to wait for all that output. Anyway this can be
+ * boot time and run time configurable.
  */
-static unsigned long		trace_nr_entries = 65536UL;
+#define TRACE_BUF_SIZE_DEFAULT	1441792UL /* 16384 * 88 (sizeof(entry)) */
+
+static unsigned long		trace_buf_size = TRACE_BUF_SIZE_DEFAULT;
 
 /* trace_types holds a link list of available tracers. */
 static struct tracer		*trace_types __read_mostly;
@@ -133,24 +155,6 @@ static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
 /* trace_flags holds iter_ctrl options */
 unsigned long trace_flags = TRACE_ITER_PRINT_PARENT;
 
-static notrace void no_trace_init(struct trace_array *tr)
-{
-	int cpu;
-
-	ftrace_function_enabled = 0;
-	if(tr->ctrl)
-		for_each_online_cpu(cpu)
-			tracing_reset(tr->data[cpu]);
-	tracer_enabled = 0;
-}
-
-/* dummy trace to disable tracing */
-static struct tracer no_tracer __read_mostly = {
-	.name		= "none",
-	.init		= no_trace_init
-};
-
-
 /**
  * trace_wake_up - wake up tasks waiting for trace input
  *
@@ -167,23 +171,21 @@ void trace_wake_up(void)
 		wake_up(&trace_wait);
 }
 
-#define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry))
-
-static int __init set_nr_entries(char *str)
+static int __init set_buf_size(char *str)
 {
-	unsigned long nr_entries;
+	unsigned long buf_size;
 	int ret;
 
 	if (!str)
 		return 0;
-	ret = strict_strtoul(str, 0, &nr_entries);
+	ret = strict_strtoul(str, 0, &buf_size);
 	/* nr_entries can not be zero */
-	if (ret < 0 || nr_entries == 0)
+	if (ret < 0 || buf_size == 0)
 		return 0;
-	trace_nr_entries = nr_entries;
+	trace_buf_size = buf_size;
 	return 1;
 }
-__setup("trace_entries=", set_nr_entries);
+__setup("trace_buf_size=", set_buf_size);
 
 unsigned long nsecs_to_usecs(unsigned long nsecs)
 {
@@ -191,21 +193,6 @@ unsigned long nsecs_to_usecs(unsigned long nsecs)
 }
 
 /*
- * trace_flag_type is an enumeration that holds different
- * states when a trace occurs. These are:
- *  IRQS_OFF	- interrupts were disabled
- *  NEED_RESCED - reschedule is requested
- *  HARDIRQ	- inside an interrupt handler
- *  SOFTIRQ	- inside a softirq handler
- */
-enum trace_flag_type {
-	TRACE_FLAG_IRQS_OFF		= 0x01,
-	TRACE_FLAG_NEED_RESCHED		= 0x02,
-	TRACE_FLAG_HARDIRQ		= 0x04,
-	TRACE_FLAG_SOFTIRQ		= 0x08,
-};
-
-/*
  * TRACE_ITER_SYM_MASK masks the options in trace_flags that
  * control the output of kernel symbols.
  */
@@ -224,6 +211,7 @@ static const char *trace_options[] = {
 	"block",
 	"stacktrace",
 	"sched-tree",
+	"ftrace_printk",
 	NULL
 };
 
@@ -266,54 +254,6 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 	tracing_record_cmdline(current);
 }
 
-#define CHECK_COND(cond)			\
-	if (unlikely(cond)) {			\
-		tracing_disabled = 1;		\
-		WARN_ON(1);			\
-		return -1;			\
-	}
-
-/**
- * check_pages - integrity check of trace buffers
- *
- * As a safty measure we check to make sure the data pages have not
- * been corrupted.
- */
-int check_pages(struct trace_array_cpu *data)
-{
-	struct page *page, *tmp;
-
-	CHECK_COND(data->trace_pages.next->prev != &data->trace_pages);
-	CHECK_COND(data->trace_pages.prev->next != &data->trace_pages);
-
-	list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) {
-		CHECK_COND(page->lru.next->prev != &page->lru);
-		CHECK_COND(page->lru.prev->next != &page->lru);
-	}
-
-	return 0;
-}
-
-/**
- * head_page - page address of the first page in per_cpu buffer.
- *
- * head_page returns the page address of the first page in
- * a per_cpu buffer. This also preforms various consistency
- * checks to make sure the buffer has not been corrupted.
- */
-void *head_page(struct trace_array_cpu *data)
-{
-	struct page *page;
-
-	if (list_empty(&data->trace_pages))
-		return NULL;
-
-	page = list_entry(data->trace_pages.next, struct page, lru);
-	BUG_ON(&page->lru == &data->trace_pages);
-
-	return page_address(page);
-}
-
 /**
  * trace_seq_printf - sequence printing of trace information
  * @s: trace sequence descriptor
@@ -395,28 +335,23 @@ trace_seq_putmem(struct trace_seq *s, void *mem, size_t len)
 	return len;
 }
 
-#define HEX_CHARS 17
-static const char hex2asc[] = "0123456789abcdef";
+#define MAX_MEMHEX_BYTES	8
+#define HEX_CHARS		(MAX_MEMHEX_BYTES*2 + 1)
 
 static int
 trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
 {
 	unsigned char hex[HEX_CHARS];
 	unsigned char *data = mem;
-	unsigned char byte;
 	int i, j;
 
-	BUG_ON(len >= HEX_CHARS);
-
 #ifdef __BIG_ENDIAN
 	for (i = 0, j = 0; i < len; i++) {
 #else
 	for (i = len-1, j = 0; i >= 0; i--) {
 #endif
-		byte = data[i];
-
-		hex[j++] = hex2asc[byte & 0x0f];
-		hex[j++] = hex2asc[byte >> 4];
+		hex[j++] = hex_asc_hi(data[i]);
+		hex[j++] = hex_asc_lo(data[i]);
 	}
 	hex[j++] = ' ';
 
@@ -460,34 +395,6 @@ trace_print_seq(struct seq_file *m, struct trace_seq *s)
 	trace_seq_reset(s);
 }
 
-/*
- * flip the trace buffers between two trace descriptors.
- * This usually is the buffers between the global_trace and
- * the max_tr to record a snapshot of a current trace.
- *
- * The ftrace_max_lock must be held.
- */
-static void
-flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2)
-{
-	struct list_head flip_pages;
-
-	INIT_LIST_HEAD(&flip_pages);
-
-	memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx,
-		sizeof(struct trace_array_cpu) -
-		offsetof(struct trace_array_cpu, trace_head_idx));
-
-	check_pages(tr1);
-	check_pages(tr2);
-	list_splice_init(&tr1->trace_pages, &flip_pages);
-	list_splice_init(&tr2->trace_pages, &tr1->trace_pages);
-	list_splice_init(&flip_pages, &tr2->trace_pages);
-	BUG_ON(!list_empty(&flip_pages));
-	check_pages(tr1);
-	check_pages(tr2);
-}
-
 /**
  * update_max_tr - snapshot all trace buffers from global_trace to max_tr
  * @tr: tracer
@@ -500,17 +407,17 @@ flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2)
 void
 update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 {
-	struct trace_array_cpu *data;
-	int i;
+	struct ring_buffer *buf = tr->buffer;
 
 	WARN_ON_ONCE(!irqs_disabled());
 	__raw_spin_lock(&ftrace_max_lock);
-	/* clear out all the previous traces */
-	for_each_tracing_cpu(i) {
-		data = tr->data[i];
-		flip_trace(max_tr.data[i], data);
-		tracing_reset(data);
-	}
+
+	tr->buffer = max_tr.buffer;
+	max_tr.buffer = buf;
+
+	ftrace_disable_cpu();
+	ring_buffer_reset(tr->buffer);
+	ftrace_enable_cpu();
 
 	__update_max_tr(tr, tsk, cpu);
 	__raw_spin_unlock(&ftrace_max_lock);
@@ -527,16 +434,19 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
 void
 update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
 {
-	struct trace_array_cpu *data = tr->data[cpu];
-	int i;
+	int ret;
 
 	WARN_ON_ONCE(!irqs_disabled());
 	__raw_spin_lock(&ftrace_max_lock);
-	for_each_tracing_cpu(i)
-		tracing_reset(max_tr.data[i]);
 
-	flip_trace(max_tr.data[cpu], data);
-	tracing_reset(data);
+	ftrace_disable_cpu();
+
+	ring_buffer_reset(max_tr.buffer);
+	ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu);
+
+	ftrace_enable_cpu();
+
+	WARN_ON_ONCE(ret);
 
 	__update_max_tr(tr, tsk, cpu);
 	__raw_spin_unlock(&ftrace_max_lock);
@@ -573,7 +483,6 @@ int register_tracer(struct tracer *type)
 #ifdef CONFIG_FTRACE_STARTUP_TEST
 	if (type->selftest) {
 		struct tracer *saved_tracer = current_trace;
-		struct trace_array_cpu *data;
 		struct trace_array *tr = &global_trace;
 		int saved_ctrl = tr->ctrl;
 		int i;
@@ -585,10 +494,7 @@ int register_tracer(struct tracer *type)
 		 * If we fail, we do not register this tracer.
 		 */
 		for_each_tracing_cpu(i) {
-			data = tr->data[i];
-			if (!head_page(data))
-				continue;
-			tracing_reset(data);
+			tracing_reset(tr, i);
 		}
 		current_trace = type;
 		tr->ctrl = 0;
@@ -604,10 +510,7 @@ int register_tracer(struct tracer *type)
 		}
 		/* Only reset on passing, to avoid touching corrupted buffers */
 		for_each_tracing_cpu(i) {
-			data = tr->data[i];
-			if (!head_page(data))
-				continue;
-			tracing_reset(data);
+			tracing_reset(tr, i);
 		}
 		printk(KERN_CONT "PASSED\n");
 	}
@@ -653,13 +556,11 @@ void unregister_tracer(struct tracer *type)
 	mutex_unlock(&trace_types_lock);
 }
 
-void tracing_reset(struct trace_array_cpu *data)
+void tracing_reset(struct trace_array *tr, int cpu)
 {
-	data->trace_idx = 0;
-	data->overrun = 0;
-	data->trace_head = data->trace_tail = head_page(data);
-	data->trace_head_idx = 0;
-	data->trace_tail_idx = 0;
+	ftrace_disable_cpu();
+	ring_buffer_reset_cpu(tr->buffer, cpu);
+	ftrace_enable_cpu();
 }
 
 #define SAVED_CMDLINES 128
@@ -745,82 +646,16 @@ void tracing_record_cmdline(struct task_struct *tsk)
 	trace_save_cmdline(tsk);
 }
 
-static inline struct list_head *
-trace_next_list(struct trace_array_cpu *data, struct list_head *next)
-{
-	/*
-	 * Roundrobin - but skip the head (which is not a real page):
-	 */
-	next = next->next;
-	if (unlikely(next == &data->trace_pages))
-		next = next->next;
-	BUG_ON(next == &data->trace_pages);
-
-	return next;
-}
-
-static inline void *
-trace_next_page(struct trace_array_cpu *data, void *addr)
-{
-	struct list_head *next;
-	struct page *page;
-
-	page = virt_to_page(addr);
-
-	next = trace_next_list(data, &page->lru);
-	page = list_entry(next, struct page, lru);
-
-	return page_address(page);
-}
-
-static inline struct trace_entry *
-tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data)
-{
-	unsigned long idx, idx_next;
-	struct trace_entry *entry;
-
-	data->trace_idx++;
-	idx = data->trace_head_idx;
-	idx_next = idx + 1;
-
-	BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE);
-
-	entry = data->trace_head + idx * TRACE_ENTRY_SIZE;
-
-	if (unlikely(idx_next >= ENTRIES_PER_PAGE)) {
-		data->trace_head = trace_next_page(data, data->trace_head);
-		idx_next = 0;
-	}
-
-	if (data->trace_head == data->trace_tail &&
-	    idx_next == data->trace_tail_idx) {
-		/* overrun */
-		data->overrun++;
-		data->trace_tail_idx++;
-		if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
-			data->trace_tail =
-				trace_next_page(data, data->trace_tail);
-			data->trace_tail_idx = 0;
-		}
-	}
-
-	data->trace_head_idx = idx_next;
-
-	return entry;
-}
-
-static inline void
-tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
+void
+tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
+			     int pc)
 {
 	struct task_struct *tsk = current;
-	unsigned long pc;
-
-	pc = preempt_count();
 
-	entry->preempt_count	= pc & 0xff;
-	entry->pid		= (tsk) ? tsk->pid : 0;
-	entry->t		= ftrace_now(raw_smp_processor_id());
-	entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
+	entry->preempt_count		= pc & 0xff;
+	entry->pid			= (tsk) ? tsk->pid : 0;
+	entry->flags =
+		(irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
 		((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
 		((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
 		(need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
@@ -828,145 +663,139 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
 
 void
 trace_function(struct trace_array *tr, struct trace_array_cpu *data,
-	       unsigned long ip, unsigned long parent_ip, unsigned long flags)
+	       unsigned long ip, unsigned long parent_ip, unsigned long flags,
+	       int pc)
 {
-	struct trace_entry *entry;
+	struct ring_buffer_event *event;
+	struct ftrace_entry *entry;
 	unsigned long irq_flags;
 
-	raw_local_irq_save(irq_flags);
-	__raw_spin_lock(&data->lock);
-	entry			= tracing_get_trace_entry(tr, data);
-	tracing_generic_entry_update(entry, flags);
-	entry->type		= TRACE_FN;
-	entry->fn.ip		= ip;
-	entry->fn.parent_ip	= parent_ip;
-	__raw_spin_unlock(&data->lock);
-	raw_local_irq_restore(irq_flags);
+	/* If we are reading the ring buffer, don't trace */
+	if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+		return;
+
+	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+					 &irq_flags);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, flags, pc);
+	entry->ent.type			= TRACE_FN;
+	entry->ip			= ip;
+	entry->parent_ip		= parent_ip;
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
 }
 
 void
 ftrace(struct trace_array *tr, struct trace_array_cpu *data,
-       unsigned long ip, unsigned long parent_ip, unsigned long flags)
+       unsigned long ip, unsigned long parent_ip, unsigned long flags,
+       int pc)
 {
 	if (likely(!atomic_read(&data->disabled)))
-		trace_function(tr, data, ip, parent_ip, flags);
+		trace_function(tr, data, ip, parent_ip, flags, pc);
 }
 
-#ifdef CONFIG_MMIOTRACE
-void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data,
-						struct mmiotrace_rw *rw)
+static void ftrace_trace_stack(struct trace_array *tr,
+			       struct trace_array_cpu *data,
+			       unsigned long flags,
+			       int skip, int pc)
 {
-	struct trace_entry *entry;
+	struct ring_buffer_event *event;
+	struct stack_entry *entry;
+	struct stack_trace trace;
 	unsigned long irq_flags;
 
-	raw_local_irq_save(irq_flags);
-	__raw_spin_lock(&data->lock);
-
-	entry			= tracing_get_trace_entry(tr, data);
-	tracing_generic_entry_update(entry, 0);
-	entry->type		= TRACE_MMIO_RW;
-	entry->mmiorw		= *rw;
-
-	__raw_spin_unlock(&data->lock);
-	raw_local_irq_restore(irq_flags);
-
-	trace_wake_up();
-}
-
-void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data,
-						struct mmiotrace_map *map)
-{
-	struct trace_entry *entry;
-	unsigned long irq_flags;
+	if (!(trace_flags & TRACE_ITER_STACKTRACE))
+		return;
 
-	raw_local_irq_save(irq_flags);
-	__raw_spin_lock(&data->lock);
+	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+					 &irq_flags);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, flags, pc);
+	entry->ent.type		= TRACE_STACK;
 
-	entry			= tracing_get_trace_entry(tr, data);
-	tracing_generic_entry_update(entry, 0);
-	entry->type		= TRACE_MMIO_MAP;
-	entry->mmiomap		= *map;
+	memset(&entry->caller, 0, sizeof(entry->caller));
 
-	__raw_spin_unlock(&data->lock);
-	raw_local_irq_restore(irq_flags);
+	trace.nr_entries	= 0;
+	trace.max_entries	= FTRACE_STACK_ENTRIES;
+	trace.skip		= skip;
+	trace.entries		= entry->caller;
 
-	trace_wake_up();
+	save_stack_trace(&trace);
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
 }
-#endif
 
 void __trace_stack(struct trace_array *tr,
 		   struct trace_array_cpu *data,
 		   unsigned long flags,
 		   int skip)
 {
-	struct trace_entry *entry;
-	struct stack_trace trace;
-
-	if (!(trace_flags & TRACE_ITER_STACKTRACE))
-		return;
-
-	entry			= tracing_get_trace_entry(tr, data);
-	tracing_generic_entry_update(entry, flags);
-	entry->type		= TRACE_STACK;
-
-	memset(&entry->stack, 0, sizeof(entry->stack));
-
-	trace.nr_entries	= 0;
-	trace.max_entries	= FTRACE_STACK_ENTRIES;
-	trace.skip		= skip;
-	trace.entries		= entry->stack.caller;
-
-	save_stack_trace(&trace);
+	ftrace_trace_stack(tr, data, flags, skip, preempt_count());
 }
 
-void
-__trace_special(void *__tr, void *__data,
-		unsigned long arg1, unsigned long arg2, unsigned long arg3)
+static void
+ftrace_trace_special(void *__tr, void *__data,
+		     unsigned long arg1, unsigned long arg2, unsigned long arg3,
+		     int pc)
 {
+	struct ring_buffer_event *event;
 	struct trace_array_cpu *data = __data;
 	struct trace_array *tr = __tr;
-	struct trace_entry *entry;
+	struct special_entry *entry;
 	unsigned long irq_flags;
 
-	raw_local_irq_save(irq_flags);
-	__raw_spin_lock(&data->lock);
-	entry			= tracing_get_trace_entry(tr, data);
-	tracing_generic_entry_update(entry, 0);
-	entry->type		= TRACE_SPECIAL;
-	entry->special.arg1	= arg1;
-	entry->special.arg2	= arg2;
-	entry->special.arg3	= arg3;
-	__trace_stack(tr, data, irq_flags, 4);
-	__raw_spin_unlock(&data->lock);
-	raw_local_irq_restore(irq_flags);
+	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+					 &irq_flags);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, 0, pc);
+	entry->ent.type			= TRACE_SPECIAL;
+	entry->arg1			= arg1;
+	entry->arg2			= arg2;
+	entry->arg3			= arg3;
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+	ftrace_trace_stack(tr, data, irq_flags, 4, pc);
 
 	trace_wake_up();
 }
 
 void
+__trace_special(void *__tr, void *__data,
+		unsigned long arg1, unsigned long arg2, unsigned long arg3)
+{
+	ftrace_trace_special(__tr, __data, arg1, arg2, arg3, preempt_count());
+}
+
+void
 tracing_sched_switch_trace(struct trace_array *tr,
 			   struct trace_array_cpu *data,
 			   struct task_struct *prev,
 			   struct task_struct *next,
-			   unsigned long flags)
+			   unsigned long flags, int pc)
 {
-	struct trace_entry *entry;
+	struct ring_buffer_event *event;
+	struct ctx_switch_entry *entry;
 	unsigned long irq_flags;
 
-	raw_local_irq_save(irq_flags);
-	__raw_spin_lock(&data->lock);
-	entry			= tracing_get_trace_entry(tr, data);
-	tracing_generic_entry_update(entry, flags);
-	entry->type		= TRACE_CTX;
-	entry->ctx.prev_pid	= prev->pid;
-	entry->ctx.prev_prio	= prev->prio;
-	entry->ctx.prev_state	= prev->state;
-	entry->ctx.next_pid	= next->pid;
-	entry->ctx.next_prio	= next->prio;
-	entry->ctx.next_state	= next->state;
-	__trace_stack(tr, data, flags, 5);
-	__raw_spin_unlock(&data->lock);
-	raw_local_irq_restore(irq_flags);
+	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+					   &irq_flags);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, flags, pc);
+	entry->ent.type			= TRACE_CTX;
+	entry->prev_pid			= prev->pid;
+	entry->prev_prio		= prev->prio;
+	entry->prev_state		= prev->state;
+	entry->next_pid			= next->pid;
+	entry->next_prio		= next->prio;
+	entry->next_state		= next->state;
+	entry->next_cpu	= task_cpu(next);
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+	ftrace_trace_stack(tr, data, flags, 5, pc);
 }
 
 void
@@ -974,25 +803,28 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
 			   struct trace_array_cpu *data,
 			   struct task_struct *wakee,
 			   struct task_struct *curr,
-			   unsigned long flags)
+			   unsigned long flags, int pc)
 {
-	struct trace_entry *entry;
+	struct ring_buffer_event *event;
+	struct ctx_switch_entry *entry;
 	unsigned long irq_flags;
 
-	raw_local_irq_save(irq_flags);
-	__raw_spin_lock(&data->lock);
-	entry			= tracing_get_trace_entry(tr, data);
-	tracing_generic_entry_update(entry, flags);
-	entry->type		= TRACE_WAKE;
-	entry->ctx.prev_pid	= curr->pid;
-	entry->ctx.prev_prio	= curr->prio;
-	entry->ctx.prev_state	= curr->state;
-	entry->ctx.next_pid	= wakee->pid;
-	entry->ctx.next_prio	= wakee->prio;
-	entry->ctx.next_state	= wakee->state;
-	__trace_stack(tr, data, flags, 6);
-	__raw_spin_unlock(&data->lock);
-	raw_local_irq_restore(irq_flags);
+	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+					   &irq_flags);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, flags, pc);
+	entry->ent.type			= TRACE_WAKE;
+	entry->prev_pid			= curr->pid;
+	entry->prev_prio		= curr->prio;
+	entry->prev_state		= curr->state;
+	entry->next_pid			= wakee->pid;
+	entry->next_prio		= wakee->prio;
+	entry->next_state		= wakee->state;
+	entry->next_cpu			= task_cpu(wakee);
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+	ftrace_trace_stack(tr, data, flags, 6, pc);
 
 	trace_wake_up();
 }
@@ -1002,23 +834,21 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
 {
 	struct trace_array *tr = &global_trace;
 	struct trace_array_cpu *data;
-	unsigned long flags;
-	long disabled;
 	int cpu;
+	int pc;
 
-	if (tracing_disabled || current_trace == &no_tracer || !tr->ctrl)
+	if (tracing_disabled || !tr->ctrl)
 		return;
 
-	local_irq_save(flags);
+	pc = preempt_count();
+	preempt_disable_notrace();
 	cpu = raw_smp_processor_id();
 	data = tr->data[cpu];
-	disabled = atomic_inc_return(&data->disabled);
 
-	if (likely(disabled == 1))
-		__trace_special(tr, data, arg1, arg2, arg3);
+	if (likely(!atomic_read(&data->disabled)))
+		ftrace_trace_special(tr, data, arg1, arg2, arg3, pc);
 
-	atomic_dec(&data->disabled);
-	local_irq_restore(flags);
+	preempt_enable_notrace();
 }
 
 #ifdef CONFIG_FTRACE
@@ -1029,7 +859,8 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
 	struct trace_array_cpu *data;
 	unsigned long flags;
 	long disabled;
-	int cpu;
+	int cpu, resched;
+	int pc;
 
 	if (unlikely(!ftrace_function_enabled))
 		return;
@@ -1037,16 +868,22 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
 	if (skip_trace(ip))
 		return;
 
-	local_irq_save(flags);
+	pc = preempt_count();
+	resched = need_resched();
+	preempt_disable_notrace();
+	local_save_flags(flags);
 	cpu = raw_smp_processor_id();
 	data = tr->data[cpu];
 	disabled = atomic_inc_return(&data->disabled);
 
 	if (likely(disabled == 1))
-		trace_function(tr, data, ip, parent_ip, flags);
+		trace_function(tr, data, ip, parent_ip, flags, pc);
 
 	atomic_dec(&data->disabled);
-	local_irq_restore(flags);
+	if (resched)
+		preempt_enable_no_resched_notrace();
+	else
+		preempt_enable_notrace();
 }
 
 static struct ftrace_ops trace_ops __read_mostly =
@@ -1073,111 +910,96 @@ enum trace_file_type {
 	TRACE_FILE_LAT_FMT	= 1,
 };
 
-static struct trace_entry *
-trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data,
-		struct trace_iterator *iter, int cpu)
+static void trace_iterator_increment(struct trace_iterator *iter, int cpu)
 {
-	struct page *page;
-	struct trace_entry *array;
+	/* Don't allow ftrace to trace into the ring buffers */
+	ftrace_disable_cpu();
 
-	if (iter->next_idx[cpu] >= tr->entries ||
-	    iter->next_idx[cpu] >= data->trace_idx ||
-	    (data->trace_head == data->trace_tail &&
-	     data->trace_head_idx == data->trace_tail_idx))
-		return NULL;
+	iter->idx++;
+	if (iter->buffer_iter[iter->cpu])
+		ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
 
-	if (!iter->next_page[cpu]) {
-		/* Initialize the iterator for this cpu trace buffer */
-		WARN_ON(!data->trace_tail);
-		page = virt_to_page(data->trace_tail);
-		iter->next_page[cpu] = &page->lru;
-		iter->next_page_idx[cpu] = data->trace_tail_idx;
-	}
+	ftrace_enable_cpu();
+}
+
+static struct trace_entry *
+peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts)
+{
+	struct ring_buffer_event *event;
+	struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu];
 
-	page = list_entry(iter->next_page[cpu], struct page, lru);
-	BUG_ON(&data->trace_pages == &page->lru);
+	/* Don't allow ftrace to trace into the ring buffers */
+	ftrace_disable_cpu();
+
+	if (buf_iter)
+		event = ring_buffer_iter_peek(buf_iter, ts);
+	else
+		event = ring_buffer_peek(iter->tr->buffer, cpu, ts);
 
-	array = page_address(page);
+	ftrace_enable_cpu();
 
-	WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE);
-	return &array[iter->next_page_idx[cpu]];
+	return event ? ring_buffer_event_data(event) : NULL;
 }
 
 static struct trace_entry *
-find_next_entry(struct trace_iterator *iter, int *ent_cpu)
+__find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
 {
-	struct trace_array *tr = iter->tr;
+	struct ring_buffer *buffer = iter->tr->buffer;
 	struct trace_entry *ent, *next = NULL;
+	u64 next_ts = 0, ts;
 	int next_cpu = -1;
 	int cpu;
 
 	for_each_tracing_cpu(cpu) {
-		if (!head_page(tr->data[cpu]))
+
+		if (ring_buffer_empty_cpu(buffer, cpu))
 			continue;
-		ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu);
+
+		ent = peek_next_entry(iter, cpu, &ts);
+
 		/*
 		 * Pick the entry with the smallest timestamp:
 		 */
-		if (ent && (!next || ent->t < next->t)) {
+		if (ent && (!next || ts < next_ts)) {
 			next = ent;
 			next_cpu = cpu;
+			next_ts = ts;
 		}
 	}
 
 	if (ent_cpu)
 		*ent_cpu = next_cpu;
 
+	if (ent_ts)
+		*ent_ts = next_ts;
+
 	return next;
 }
 
-static void trace_iterator_increment(struct trace_iterator *iter)
+/* Find the next real entry, without updating the iterator itself */
+static struct trace_entry *
+find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts)
 {
-	iter->idx++;
-	iter->next_idx[iter->cpu]++;
-	iter->next_page_idx[iter->cpu]++;
-
-	if (iter->next_page_idx[iter->cpu] >= ENTRIES_PER_PAGE) {
-		struct trace_array_cpu *data = iter->tr->data[iter->cpu];
-
-		iter->next_page_idx[iter->cpu] = 0;
-		iter->next_page[iter->cpu] =
-			trace_next_list(data, iter->next_page[iter->cpu]);
-	}
+	return __find_next_entry(iter, ent_cpu, ent_ts);
 }
 
-static void trace_consume(struct trace_iterator *iter)
+/* Find the next real entry, and increment the iterator to the next entry */
+static void *find_next_entry_inc(struct trace_iterator *iter)
 {
-	struct trace_array_cpu *data = iter->tr->data[iter->cpu];
+	iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts);
 
-	data->trace_tail_idx++;
-	if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
-		data->trace_tail = trace_next_page(data, data->trace_tail);
-		data->trace_tail_idx = 0;
-	}
+	if (iter->ent)
+		trace_iterator_increment(iter, iter->cpu);
 
-	/* Check if we empty it, then reset the index */
-	if (data->trace_head == data->trace_tail &&
-	    data->trace_head_idx == data->trace_tail_idx)
-		data->trace_idx = 0;
+	return iter->ent ? iter : NULL;
 }
 
-static void *find_next_entry_inc(struct trace_iterator *iter)
+static void trace_consume(struct trace_iterator *iter)
 {
-	struct trace_entry *next;
-	int next_cpu = -1;
-
-	next = find_next_entry(iter, &next_cpu);
-
-	iter->prev_ent = iter->ent;
-	iter->prev_cpu = iter->cpu;
-
-	iter->ent = next;
-	iter->cpu = next_cpu;
-
-	if (next)
-		trace_iterator_increment(iter);
-
-	return next ? iter : NULL;
+	/* Don't allow ftrace to trace into the ring buffers */
+	ftrace_disable_cpu();
+	ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts);
+	ftrace_enable_cpu();
 }
 
 static void *s_next(struct seq_file *m, void *v, loff_t *pos)
@@ -1210,7 +1032,7 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 	struct trace_iterator *iter = m->private;
 	void *p = NULL;
 	loff_t l = 0;
-	int i;
+	int cpu;
 
 	mutex_lock(&trace_types_lock);
 
@@ -1229,14 +1051,15 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 		iter->ent = NULL;
 		iter->cpu = 0;
 		iter->idx = -1;
-		iter->prev_ent = NULL;
-		iter->prev_cpu = -1;
 
-		for_each_tracing_cpu(i) {
-			iter->next_idx[i] = 0;
-			iter->next_page[i] = NULL;
+		ftrace_disable_cpu();
+
+		for_each_tracing_cpu(cpu) {
+			ring_buffer_iter_reset(iter->buffer_iter[cpu]);
 		}
 
+		ftrace_enable_cpu();
+
 		for (p = iter; p && l < *pos; p = s_next(m, p, &l))
 			;
 
@@ -1330,21 +1153,21 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 
 static void print_lat_help_header(struct seq_file *m)
 {
-	seq_puts(m, "#                _------=> CPU#            \n");
-	seq_puts(m, "#               / _-----=> irqs-off        \n");
-	seq_puts(m, "#              | / _----=> need-resched    \n");
-	seq_puts(m, "#              || / _---=> hardirq/softirq \n");
-	seq_puts(m, "#              ||| / _--=> preempt-depth   \n");
-	seq_puts(m, "#              |||| /                      \n");
-	seq_puts(m, "#              |||||     delay             \n");
-	seq_puts(m, "#  cmd     pid ||||| time  |   caller      \n");
-	seq_puts(m, "#     \\   /    |||||   \\   |   /           \n");
+	seq_puts(m, "#                  _------=> CPU#            \n");
+	seq_puts(m, "#                 / _-----=> irqs-off        \n");
+	seq_puts(m, "#                | / _----=> need-resched    \n");
+	seq_puts(m, "#                || / _---=> hardirq/softirq \n");
+	seq_puts(m, "#                ||| / _--=> preempt-depth   \n");
+	seq_puts(m, "#                |||| /                      \n");
+	seq_puts(m, "#                |||||     delay             \n");
+	seq_puts(m, "#  cmd     pid   ||||| time  |   caller      \n");
+	seq_puts(m, "#     \\   /      |||||   \\   |   /           \n");
 }
 
 static void print_func_help_header(struct seq_file *m)
 {
-	seq_puts(m, "#           TASK-PID   CPU#    TIMESTAMP  FUNCTION\n");
-	seq_puts(m, "#              | |      |          |         |\n");
+	seq_puts(m, "#           TASK-PID    CPU#    TIMESTAMP  FUNCTION\n");
+	seq_puts(m, "#              | |       |          |         |\n");
 }
 
 
@@ -1355,23 +1178,16 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
 	struct trace_array *tr = iter->tr;
 	struct trace_array_cpu *data = tr->data[tr->cpu];
 	struct tracer *type = current_trace;
-	unsigned long total   = 0;
-	unsigned long entries = 0;
-	int cpu;
+	unsigned long total;
+	unsigned long entries;
 	const char *name = "preemption";
 
 	if (type)
 		name = type->name;
 
-	for_each_tracing_cpu(cpu) {
-		if (head_page(tr->data[cpu])) {
-			total += tr->data[cpu]->trace_idx;
-			if (tr->data[cpu]->trace_idx > tr->entries)
-				entries += tr->entries;
-			else
-				entries += tr->data[cpu]->trace_idx;
-		}
-	}
+	entries = ring_buffer_entries(iter->tr->buffer);
+	total = entries +
+		ring_buffer_overruns(iter->tr->buffer);
 
 	seq_printf(m, "%s latency trace v1.1.5 on %s\n",
 		   name, UTS_RELEASE);
@@ -1428,7 +1244,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 	comm = trace_find_cmdline(entry->pid);
 
 	trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid);
-	trace_seq_printf(s, "%d", cpu);
+	trace_seq_printf(s, "%3d", cpu);
 	trace_seq_printf(s, "%c%c",
 			(entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.',
 			((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
@@ -1457,7 +1273,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
 unsigned long preempt_mark_thresh = 100;
 
 static void
-lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
+lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
 		    unsigned long rel_usecs)
 {
 	trace_seq_printf(s, " %4lldus", abs_usecs);
@@ -1471,34 +1287,76 @@ lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
 
 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 
-static int
+/*
+ * The message is supposed to contain an ending newline.
+ * If the printing stops prematurely, try to add a newline of our own.
+ */
+void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter)
+{
+	struct trace_entry *ent;
+	struct trace_field_cont *cont;
+	bool ok = true;
+
+	ent = peek_next_entry(iter, iter->cpu, NULL);
+	if (!ent || ent->type != TRACE_CONT) {
+		trace_seq_putc(s, '\n');
+		return;
+	}
+
+	do {
+		cont = (struct trace_field_cont *)ent;
+		if (ok)
+			ok = (trace_seq_printf(s, "%s", cont->buf) > 0);
+
+		ftrace_disable_cpu();
+
+		if (iter->buffer_iter[iter->cpu])
+			ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
+		else
+			ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
+
+		ftrace_enable_cpu();
+
+		ent = peek_next_entry(iter, iter->cpu, NULL);
+	} while (ent && ent->type == TRACE_CONT);
+
+	if (!ok)
+		trace_seq_putc(s, '\n');
+}
+
+static enum print_line_t
 print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 {
 	struct trace_seq *s = &iter->seq;
 	unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
-	struct trace_entry *next_entry = find_next_entry(iter, NULL);
+	struct trace_entry *next_entry;
 	unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
 	struct trace_entry *entry = iter->ent;
 	unsigned long abs_usecs;
 	unsigned long rel_usecs;
+	u64 next_ts;
 	char *comm;
 	int S, T;
 	int i;
 	unsigned state;
 
+	if (entry->type == TRACE_CONT)
+		return TRACE_TYPE_HANDLED;
+
+	next_entry = find_next_entry(iter, NULL, &next_ts);
 	if (!next_entry)
-		next_entry = entry;
-	rel_usecs = ns2usecs(next_entry->t - entry->t);
-	abs_usecs = ns2usecs(entry->t - iter->tr->time_start);
+		next_ts = iter->ts;
+	rel_usecs = ns2usecs(next_ts - iter->ts);
+	abs_usecs = ns2usecs(iter->ts - iter->tr->time_start);
 
 	if (verbose) {
 		comm = trace_find_cmdline(entry->pid);
-		trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]"
+		trace_seq_printf(s, "%16s %5d %3d %d %08x %08x [%08lx]"
 				 " %ld.%03ldms (+%ld.%03ldms): ",
 				 comm,
 				 entry->pid, cpu, entry->flags,
 				 entry->preempt_count, trace_idx,
-				 ns2usecs(entry->t),
+				 ns2usecs(iter->ts),
 				 abs_usecs/1000,
 				 abs_usecs % 1000, rel_usecs/1000,
 				 rel_usecs % 1000);
@@ -1507,52 +1365,85 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 		lat_print_timestamp(s, abs_usecs, rel_usecs);
 	}
 	switch (entry->type) {
-	case TRACE_FN:
-		seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+	case TRACE_FN: {
+		struct ftrace_entry *field;
+
+		trace_assign_type(field, entry);
+
+		seq_print_ip_sym(s, field->ip, sym_flags);
 		trace_seq_puts(s, " (");
-		if (kretprobed(entry->fn.parent_ip))
+		if (kretprobed(field->parent_ip))
 			trace_seq_puts(s, KRETPROBE_MSG);
 		else
-			seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags);
+			seq_print_ip_sym(s, field->parent_ip, sym_flags);
 		trace_seq_puts(s, ")\n");
 		break;
+	}
 	case TRACE_CTX:
-	case TRACE_WAKE:
-		T = entry->ctx.next_state < sizeof(state_to_char) ?
-			state_to_char[entry->ctx.next_state] : 'X';
+	case TRACE_WAKE: {
+		struct ctx_switch_entry *field;
+
+		trace_assign_type(field, entry);
+
+		T = field->next_state < sizeof(state_to_char) ?
+			state_to_char[field->next_state] : 'X';
 
-		state = entry->ctx.prev_state ? __ffs(entry->ctx.prev_state) + 1 : 0;
+		state = field->prev_state ?
+			__ffs(field->prev_state) + 1 : 0;
 		S = state < sizeof(state_to_char) - 1 ? state_to_char[state] : 'X';
-		comm = trace_find_cmdline(entry->ctx.next_pid);
-		trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c %s\n",
-				 entry->ctx.prev_pid,
-				 entry->ctx.prev_prio,
+		comm = trace_find_cmdline(field->next_pid);
+		trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
+				 field->prev_pid,
+				 field->prev_prio,
 				 S, entry->type == TRACE_CTX ? "==>" : "  +",
-				 entry->ctx.next_pid,
-				 entry->ctx.next_prio,
+				 field->next_cpu,
+				 field->next_pid,
+				 field->next_prio,
 				 T, comm);
 		break;
-	case TRACE_SPECIAL:
+	}
+	case TRACE_SPECIAL: {
+		struct special_entry *field;
+
+		trace_assign_type(field, entry);
+
 		trace_seq_printf(s, "# %ld %ld %ld\n",
-				 entry->special.arg1,
-				 entry->special.arg2,
-				 entry->special.arg3);
+				 field->arg1,
+				 field->arg2,
+				 field->arg3);
 		break;
-	case TRACE_STACK:
+	}
+	case TRACE_STACK: {
+		struct stack_entry *field;
+
+		trace_assign_type(field, entry);
+
 		for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
 			if (i)
 				trace_seq_puts(s, " <= ");
-			seq_print_ip_sym(s, entry->stack.caller[i], sym_flags);
+			seq_print_ip_sym(s, field->caller[i], sym_flags);
 		}
 		trace_seq_puts(s, "\n");
 		break;
+	}
+	case TRACE_PRINT: {
+		struct print_entry *field;
+
+		trace_assign_type(field, entry);
+
+		seq_print_ip_sym(s, field->ip, sym_flags);
+		trace_seq_printf(s, ": %s", field->buf);
+		if (entry->flags & TRACE_FLAG_CONT)
+			trace_seq_print_cont(s, iter);
+		break;
+	}
 	default:
 		trace_seq_printf(s, "Unknown type %d\n", entry->type);
 	}
-	return 1;
+	return TRACE_TYPE_HANDLED;
 }
 
-static int print_trace_fmt(struct trace_iterator *iter)
+static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 {
 	struct trace_seq *s = &iter->seq;
 	unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
@@ -1567,90 +1458,126 @@ static int print_trace_fmt(struct trace_iterator *iter)
 
 	entry = iter->ent;
 
+	if (entry->type == TRACE_CONT)
+		return TRACE_TYPE_HANDLED;
+
 	comm = trace_find_cmdline(iter->ent->pid);
 
-	t = ns2usecs(entry->t);
+	t = ns2usecs(iter->ts);
 	usec_rem = do_div(t, 1000000ULL);
 	secs = (unsigned long)t;
 
 	ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
 	if (!ret)
-		return 0;
-	ret = trace_seq_printf(s, "[%02d] ", iter->cpu);
+		return TRACE_TYPE_PARTIAL_LINE;
+	ret = trace_seq_printf(s, "[%03d] ", iter->cpu);
 	if (!ret)
-		return 0;
+		return TRACE_TYPE_PARTIAL_LINE;
 	ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
 	if (!ret)
-		return 0;
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	switch (entry->type) {
-	case TRACE_FN:
-		ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+	case TRACE_FN: {
+		struct ftrace_entry *field;
+
+		trace_assign_type(field, entry);
+
+		ret = seq_print_ip_sym(s, field->ip, sym_flags);
 		if (!ret)
-			return 0;
+			return TRACE_TYPE_PARTIAL_LINE;
 		if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
-						entry->fn.parent_ip) {
+						field->parent_ip) {
 			ret = trace_seq_printf(s, " <-");
 			if (!ret)
-				return 0;
-			if (kretprobed(entry->fn.parent_ip))
+				return TRACE_TYPE_PARTIAL_LINE;
+			if (kretprobed(field->parent_ip))
 				ret = trace_seq_puts(s, KRETPROBE_MSG);
 			else
-				ret = seq_print_ip_sym(s, entry->fn.parent_ip,
+				ret = seq_print_ip_sym(s,
+						       field->parent_ip,
 						       sym_flags);
 			if (!ret)
-				return 0;
+				return TRACE_TYPE_PARTIAL_LINE;
 		}
 		ret = trace_seq_printf(s, "\n");
 		if (!ret)
-			return 0;
+			return TRACE_TYPE_PARTIAL_LINE;
 		break;
+	}
 	case TRACE_CTX:
-	case TRACE_WAKE:
-		S = entry->ctx.prev_state < sizeof(state_to_char) ?
-			state_to_char[entry->ctx.prev_state] : 'X';
-		T = entry->ctx.next_state < sizeof(state_to_char) ?
-			state_to_char[entry->ctx.next_state] : 'X';
-		ret = trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c\n",
-				       entry->ctx.prev_pid,
-				       entry->ctx.prev_prio,
+	case TRACE_WAKE: {
+		struct ctx_switch_entry *field;
+
+		trace_assign_type(field, entry);
+
+		S = field->prev_state < sizeof(state_to_char) ?
+			state_to_char[field->prev_state] : 'X';
+		T = field->next_state < sizeof(state_to_char) ?
+			state_to_char[field->next_state] : 'X';
+		ret = trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n",
+				       field->prev_pid,
+				       field->prev_prio,
 				       S,
 				       entry->type == TRACE_CTX ? "==>" : "  +",
-				       entry->ctx.next_pid,
-				       entry->ctx.next_prio,
+				       field->next_cpu,
+				       field->next_pid,
+				       field->next_prio,
 				       T);
 		if (!ret)
-			return 0;
+			return TRACE_TYPE_PARTIAL_LINE;
 		break;
-	case TRACE_SPECIAL:
+	}
+	case TRACE_SPECIAL: {
+		struct special_entry *field;
+
+		trace_assign_type(field, entry);
+
 		ret = trace_seq_printf(s, "# %ld %ld %ld\n",
-				 entry->special.arg1,
-				 entry->special.arg2,
-				 entry->special.arg3);
+				 field->arg1,
+				 field->arg2,
+				 field->arg3);
 		if (!ret)
-			return 0;
+			return TRACE_TYPE_PARTIAL_LINE;
 		break;
-	case TRACE_STACK:
+	}
+	case TRACE_STACK: {
+		struct stack_entry *field;
+
+		trace_assign_type(field, entry);
+
 		for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
 			if (i) {
 				ret = trace_seq_puts(s, " <= ");
 				if (!ret)
-					return 0;
+					return TRACE_TYPE_PARTIAL_LINE;
 			}
-			ret = seq_print_ip_sym(s, entry->stack.caller[i],
+			ret = seq_print_ip_sym(s, field->caller[i],
 					       sym_flags);
 			if (!ret)
-				return 0;
+				return TRACE_TYPE_PARTIAL_LINE;
 		}
 		ret = trace_seq_puts(s, "\n");
 		if (!ret)
-			return 0;
+			return TRACE_TYPE_PARTIAL_LINE;
 		break;
 	}
-	return 1;
+	case TRACE_PRINT: {
+		struct print_entry *field;
+
+		trace_assign_type(field, entry);
+
+		seq_print_ip_sym(s, field->ip, sym_flags);
+		trace_seq_printf(s, ": %s", field->buf);
+		if (entry->flags & TRACE_FLAG_CONT)
+			trace_seq_print_cont(s, iter);
+		break;
+	}
+	}
+	return TRACE_TYPE_HANDLED;
 }
 
-static int print_raw_fmt(struct trace_iterator *iter)
+static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
 {
 	struct trace_seq *s = &iter->seq;
 	struct trace_entry *entry;
@@ -1659,47 +1586,77 @@ static int print_raw_fmt(struct trace_iterator *iter)
 
 	entry = iter->ent;
 
+	if (entry->type == TRACE_CONT)
+		return TRACE_TYPE_HANDLED;
+
 	ret = trace_seq_printf(s, "%d %d %llu ",
-		entry->pid, iter->cpu, entry->t);
+		entry->pid, iter->cpu, iter->ts);
 	if (!ret)
-		return 0;
+		return TRACE_TYPE_PARTIAL_LINE;
 
 	switch (entry->type) {
-	case TRACE_FN:
+	case TRACE_FN: {
+		struct ftrace_entry *field;
+
+		trace_assign_type(field, entry);
+
 		ret = trace_seq_printf(s, "%x %x\n",
-					entry->fn.ip, entry->fn.parent_ip);
+					field->ip,
+					field->parent_ip);
 		if (!ret)
-			return 0;
+			return TRACE_TYPE_PARTIAL_LINE;
 		break;
+	}
 	case TRACE_CTX:
-	case TRACE_WAKE:
-		S = entry->ctx.prev_state < sizeof(state_to_char) ?
-			state_to_char[entry->ctx.prev_state] : 'X';
-		T = entry->ctx.next_state < sizeof(state_to_char) ?
-			state_to_char[entry->ctx.next_state] : 'X';
+	case TRACE_WAKE: {
+		struct ctx_switch_entry *field;
+
+		trace_assign_type(field, entry);
+
+		S = field->prev_state < sizeof(state_to_char) ?
+			state_to_char[field->prev_state] : 'X';
+		T = field->next_state < sizeof(state_to_char) ?
+			state_to_char[field->next_state] : 'X';
 		if (entry->type == TRACE_WAKE)
 			S = '+';
-		ret = trace_seq_printf(s, "%d %d %c %d %d %c\n",
-				       entry->ctx.prev_pid,
-				       entry->ctx.prev_prio,
+		ret = trace_seq_printf(s, "%d %d %c %d %d %d %c\n",
+				       field->prev_pid,
+				       field->prev_prio,
 				       S,
-				       entry->ctx.next_pid,
-				       entry->ctx.next_prio,
+				       field->next_cpu,
+				       field->next_pid,
+				       field->next_prio,
 				       T);
 		if (!ret)
-			return 0;
+			return TRACE_TYPE_PARTIAL_LINE;
 		break;
+	}
 	case TRACE_SPECIAL:
-	case TRACE_STACK:
+	case TRACE_STACK: {
+		struct special_entry *field;
+
+		trace_assign_type(field, entry);
+
 		ret = trace_seq_printf(s, "# %ld %ld %ld\n",
-				 entry->special.arg1,
-				 entry->special.arg2,
-				 entry->special.arg3);
+				 field->arg1,
+				 field->arg2,
+				 field->arg3);
 		if (!ret)
-			return 0;
+			return TRACE_TYPE_PARTIAL_LINE;
 		break;
 	}
-	return 1;
+	case TRACE_PRINT: {
+		struct print_entry *field;
+
+		trace_assign_type(field, entry);
+
+		trace_seq_printf(s, "# %lx %s", field->ip, field->buf);
+		if (entry->flags & TRACE_FLAG_CONT)
+			trace_seq_print_cont(s, iter);
+		break;
+	}
+	}
+	return TRACE_TYPE_HANDLED;
 }
 
 #define SEQ_PUT_FIELD_RET(s, x)				\
@@ -1710,11 +1667,12 @@ do {							\
 
 #define SEQ_PUT_HEX_FIELD_RET(s, x)			\
 do {							\
+	BUILD_BUG_ON(sizeof(x) > MAX_MEMHEX_BYTES);	\
 	if (!trace_seq_putmem_hex(s, &(x), sizeof(x)))	\
 		return 0;				\
 } while (0)
 
-static int print_hex_fmt(struct trace_iterator *iter)
+static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
 {
 	struct trace_seq *s = &iter->seq;
 	unsigned char newline = '\n';
@@ -1723,97 +1681,139 @@ static int print_hex_fmt(struct trace_iterator *iter)
 
 	entry = iter->ent;
 
+	if (entry->type == TRACE_CONT)
+		return TRACE_TYPE_HANDLED;
+
 	SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
 	SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
-	SEQ_PUT_HEX_FIELD_RET(s, entry->t);
+	SEQ_PUT_HEX_FIELD_RET(s, iter->ts);
 
 	switch (entry->type) {
-	case TRACE_FN:
-		SEQ_PUT_HEX_FIELD_RET(s, entry->fn.ip);
-		SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
+	case TRACE_FN: {
+		struct ftrace_entry *field;
+
+		trace_assign_type(field, entry);
+
+		SEQ_PUT_HEX_FIELD_RET(s, field->ip);
+		SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
 		break;
+	}
 	case TRACE_CTX:
-	case TRACE_WAKE:
-		S = entry->ctx.prev_state < sizeof(state_to_char) ?
-			state_to_char[entry->ctx.prev_state] : 'X';
-		T = entry->ctx.next_state < sizeof(state_to_char) ?
-			state_to_char[entry->ctx.next_state] : 'X';
+	case TRACE_WAKE: {
+		struct ctx_switch_entry *field;
+
+		trace_assign_type(field, entry);
+
+		S = field->prev_state < sizeof(state_to_char) ?
+			state_to_char[field->prev_state] : 'X';
+		T = field->next_state < sizeof(state_to_char) ?
+			state_to_char[field->next_state] : 'X';
 		if (entry->type == TRACE_WAKE)
 			S = '+';
-		SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_pid);
-		SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_prio);
+		SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
+		SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
 		SEQ_PUT_HEX_FIELD_RET(s, S);
-		SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_pid);
-		SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_prio);
-		SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
+		SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
+		SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
+		SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
 		SEQ_PUT_HEX_FIELD_RET(s, T);
 		break;
+	}
 	case TRACE_SPECIAL:
-	case TRACE_STACK:
-		SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg1);
-		SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg2);
-		SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg3);
+	case TRACE_STACK: {
+		struct special_entry *field;
+
+		trace_assign_type(field, entry);
+
+		SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
+		SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
+		SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
 		break;
 	}
+	}
 	SEQ_PUT_FIELD_RET(s, newline);
 
-	return 1;
+	return TRACE_TYPE_HANDLED;
 }
 
-static int print_bin_fmt(struct trace_iterator *iter)
+static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
 {
 	struct trace_seq *s = &iter->seq;
 	struct trace_entry *entry;
 
 	entry = iter->ent;
 
+	if (entry->type == TRACE_CONT)
+		return TRACE_TYPE_HANDLED;
+
 	SEQ_PUT_FIELD_RET(s, entry->pid);
-	SEQ_PUT_FIELD_RET(s, entry->cpu);
-	SEQ_PUT_FIELD_RET(s, entry->t);
+	SEQ_PUT_FIELD_RET(s, iter->cpu);
+	SEQ_PUT_FIELD_RET(s, iter->ts);
 
 	switch (entry->type) {
-	case TRACE_FN:
-		SEQ_PUT_FIELD_RET(s, entry->fn.ip);
-		SEQ_PUT_FIELD_RET(s, entry->fn.parent_ip);
+	case TRACE_FN: {
+		struct ftrace_entry *field;
+
+		trace_assign_type(field, entry);
+
+		SEQ_PUT_FIELD_RET(s, field->ip);
+		SEQ_PUT_FIELD_RET(s, field->parent_ip);
 		break;
-	case TRACE_CTX:
-		SEQ_PUT_FIELD_RET(s, entry->ctx.prev_pid);
-		SEQ_PUT_FIELD_RET(s, entry->ctx.prev_prio);
-		SEQ_PUT_FIELD_RET(s, entry->ctx.prev_state);
-		SEQ_PUT_FIELD_RET(s, entry->ctx.next_pid);
-		SEQ_PUT_FIELD_RET(s, entry->ctx.next_prio);
-		SEQ_PUT_FIELD_RET(s, entry->ctx.next_state);
+	}
+	case TRACE_CTX: {
+		struct ctx_switch_entry *field;
+
+		trace_assign_type(field, entry);
+
+		SEQ_PUT_FIELD_RET(s, field->prev_pid);
+		SEQ_PUT_FIELD_RET(s, field->prev_prio);
+		SEQ_PUT_FIELD_RET(s, field->prev_state);
+		SEQ_PUT_FIELD_RET(s, field->next_pid);
+		SEQ_PUT_FIELD_RET(s, field->next_prio);
+		SEQ_PUT_FIELD_RET(s, field->next_state);
 		break;
+	}
 	case TRACE_SPECIAL:
-	case TRACE_STACK:
-		SEQ_PUT_FIELD_RET(s, entry->special.arg1);
-		SEQ_PUT_FIELD_RET(s, entry->special.arg2);
-		SEQ_PUT_FIELD_RET(s, entry->special.arg3);
+	case TRACE_STACK: {
+		struct special_entry *field;
+
+		trace_assign_type(field, entry);
+
+		SEQ_PUT_FIELD_RET(s, field->arg1);
+		SEQ_PUT_FIELD_RET(s, field->arg2);
+		SEQ_PUT_FIELD_RET(s, field->arg3);
 		break;
 	}
+	}
 	return 1;
 }
 
 static int trace_empty(struct trace_iterator *iter)
 {
-	struct trace_array_cpu *data;
 	int cpu;
 
 	for_each_tracing_cpu(cpu) {
-		data = iter->tr->data[cpu];
-
-		if (head_page(data) && data->trace_idx &&
-		    (data->trace_tail != data->trace_head ||
-		     data->trace_tail_idx != data->trace_head_idx))
-			return 0;
+		if (iter->buffer_iter[cpu]) {
+			if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
+				return 0;
+		} else {
+			if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu))
+				return 0;
+		}
 	}
+
 	return 1;
 }
 
-static int print_trace_line(struct trace_iterator *iter)
+static enum print_line_t print_trace_line(struct trace_iterator *iter)
 {
-	if (iter->trace && iter->trace->print_line)
-		return iter->trace->print_line(iter);
+	enum print_line_t ret;
+
+	if (iter->trace && iter->trace->print_line) {
+		ret = iter->trace->print_line(iter);
+		if (ret != TRACE_TYPE_UNHANDLED)
+			return ret;
+	}
 
 	if (trace_flags & TRACE_ITER_BIN)
 		return print_bin_fmt(iter);
@@ -1869,6 +1869,8 @@ static struct trace_iterator *
 __tracing_open(struct inode *inode, struct file *file, int *ret)
 {
 	struct trace_iterator *iter;
+	struct seq_file *m;
+	int cpu;
 
 	if (tracing_disabled) {
 		*ret = -ENODEV;
@@ -1889,28 +1891,45 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
 	iter->trace = current_trace;
 	iter->pos = -1;
 
+	for_each_tracing_cpu(cpu) {
+
+		iter->buffer_iter[cpu] =
+			ring_buffer_read_start(iter->tr->buffer, cpu);
+
+		if (!iter->buffer_iter[cpu])
+			goto fail_buffer;
+	}
+
 	/* TODO stop tracer */
 	*ret = seq_open(file, &tracer_seq_ops);
-	if (!*ret) {
-		struct seq_file *m = file->private_data;
-		m->private = iter;
+	if (*ret)
+		goto fail_buffer;
 
-		/* stop the trace while dumping */
-		if (iter->tr->ctrl) {
-			tracer_enabled = 0;
-			ftrace_function_enabled = 0;
-		}
+	m = file->private_data;
+	m->private = iter;
 
-		if (iter->trace && iter->trace->open)
-			iter->trace->open(iter);
-	} else {
-		kfree(iter);
-		iter = NULL;
+	/* stop the trace while dumping */
+	if (iter->tr->ctrl) {
+		tracer_enabled = 0;
+		ftrace_function_enabled = 0;
 	}
+
+	if (iter->trace && iter->trace->open)
+			iter->trace->open(iter);
+
 	mutex_unlock(&trace_types_lock);
 
  out:
 	return iter;
+
+ fail_buffer:
+	for_each_tracing_cpu(cpu) {
+		if (iter->buffer_iter[cpu])
+			ring_buffer_read_finish(iter->buffer_iter[cpu]);
+	}
+	mutex_unlock(&trace_types_lock);
+
+	return ERR_PTR(-ENOMEM);
 }
 
 int tracing_open_generic(struct inode *inode, struct file *filp)
@@ -1926,8 +1945,14 @@ int tracing_release(struct inode *inode, struct file *file)
 {
 	struct seq_file *m = (struct seq_file *)file->private_data;
 	struct trace_iterator *iter = m->private;
+	int cpu;
 
 	mutex_lock(&trace_types_lock);
+	for_each_tracing_cpu(cpu) {
+		if (iter->buffer_iter[cpu])
+			ring_buffer_read_finish(iter->buffer_iter[cpu]);
+	}
+
 	if (iter->trace && iter->trace->close)
 		iter->trace->close(iter);
 
@@ -2352,9 +2377,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
 	struct tracer *t;
 	char buf[max_tracer_type_len+1];
 	int i;
+	size_t ret;
 
 	if (cnt > max_tracer_type_len)
 		cnt = max_tracer_type_len;
+	ret = cnt;
 
 	if (copy_from_user(&buf, ubuf, cnt))
 		return -EFAULT;
@@ -2370,7 +2397,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
 		if (strcmp(t->name, buf) == 0)
 			break;
 	}
-	if (!t || t == current_trace)
+	if (!t) {
+		ret = -EINVAL;
+		goto out;
+	}
+	if (t == current_trace)
 		goto out;
 
 	if (current_trace && current_trace->reset)
@@ -2383,9 +2414,10 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
  out:
 	mutex_unlock(&trace_types_lock);
 
-	filp->f_pos += cnt;
+	if (ret == cnt)
+		filp->f_pos += cnt;
 
-	return cnt;
+	return ret;
 }
 
 static ssize_t
@@ -2500,20 +2532,12 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
 		  size_t cnt, loff_t *ppos)
 {
 	struct trace_iterator *iter = filp->private_data;
-	struct trace_array_cpu *data;
-	static cpumask_t mask;
-	unsigned long flags;
-#ifdef CONFIG_FTRACE
-	int ftrace_save;
-#endif
-	int cpu;
 	ssize_t sret;
 
 	/* return any leftover data */
 	sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
 	if (sret != -EBUSY)
 		return sret;
-	sret = 0;
 
 	trace_seq_reset(&iter->seq);
 
@@ -2524,6 +2548,8 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
 			goto out;
 	}
 
+waitagain:
+	sret = 0;
 	while (trace_empty(iter)) {
 
 		if ((filp->f_flags & O_NONBLOCK)) {
@@ -2588,46 +2614,12 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
 	       offsetof(struct trace_iterator, seq));
 	iter->pos = -1;
 
-	/*
-	 * We need to stop all tracing on all CPUS to read the
-	 * the next buffer. This is a bit expensive, but is
-	 * not done often. We fill all what we can read,
-	 * and then release the locks again.
-	 */
-
-	cpus_clear(mask);
-	local_irq_save(flags);
-#ifdef CONFIG_FTRACE
-	ftrace_save = ftrace_enabled;
-	ftrace_enabled = 0;
-#endif
-	smp_wmb();
-	for_each_tracing_cpu(cpu) {
-		data = iter->tr->data[cpu];
-
-		if (!head_page(data) || !data->trace_idx)
-			continue;
-
-		atomic_inc(&data->disabled);
-		cpu_set(cpu, mask);
-	}
-
-	for_each_cpu_mask(cpu, mask) {
-		data = iter->tr->data[cpu];
-		__raw_spin_lock(&data->lock);
-
-		if (data->overrun > iter->last_overrun[cpu])
-			iter->overrun[cpu] +=
-				data->overrun - iter->last_overrun[cpu];
-		iter->last_overrun[cpu] = data->overrun;
-	}
-
 	while (find_next_entry_inc(iter) != NULL) {
-		int ret;
+		enum print_line_t ret;
 		int len = iter->seq.len;
 
 		ret = print_trace_line(iter);
-		if (!ret) {
+		if (ret == TRACE_TYPE_PARTIAL_LINE) {
 			/* don't print partial lines */
 			iter->seq.len = len;
 			break;
@@ -2639,26 +2631,17 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
 			break;
 	}
 
-	for_each_cpu_mask(cpu, mask) {
-		data = iter->tr->data[cpu];
-		__raw_spin_unlock(&data->lock);
-	}
-
-	for_each_cpu_mask(cpu, mask) {
-		data = iter->tr->data[cpu];
-		atomic_dec(&data->disabled);
-	}
-#ifdef CONFIG_FTRACE
-	ftrace_enabled = ftrace_save;
-#endif
-	local_irq_restore(flags);
-
 	/* Now copy what we have to the user */
 	sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
 	if (iter->seq.readpos >= iter->seq.len)
 		trace_seq_reset(&iter->seq);
+
+	/*
+	 * If there was nothing to send to user, inspite of consuming trace
+	 * entries, go back to wait for more entries.
+	 */
 	if (sret == -EBUSY)
-		sret = 0;
+		goto waitagain;
 
 out:
 	mutex_unlock(&trace_types_lock);
@@ -2684,7 +2667,8 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 {
 	unsigned long val;
 	char buf[64];
-	int i, ret;
+	int ret;
+	struct trace_array *tr = filp->private_data;
 
 	if (cnt >= sizeof(buf))
 		return -EINVAL;
@@ -2704,59 +2688,38 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 
 	mutex_lock(&trace_types_lock);
 
-	if (current_trace != &no_tracer) {
+	if (tr->ctrl) {
 		cnt = -EBUSY;
-		pr_info("ftrace: set current_tracer to none"
+		pr_info("ftrace: please disable tracing"
 			" before modifying buffer size\n");
 		goto out;
 	}
 
-	if (val > global_trace.entries) {
-		long pages_requested;
-		unsigned long freeable_pages;
-
-		/* make sure we have enough memory before mapping */
-		pages_requested =
-			(val + (ENTRIES_PER_PAGE-1)) / ENTRIES_PER_PAGE;
-
-		/* account for each buffer (and max_tr) */
-		pages_requested *= tracing_nr_buffers * 2;
-
-		/* Check for overflow */
-		if (pages_requested < 0) {
-			cnt = -ENOMEM;
-			goto out;
-		}
-
-		freeable_pages = determine_dirtyable_memory();
-
-		/* we only allow to request 1/4 of useable memory */
-		if (pages_requested >
-		    ((freeable_pages + tracing_pages_allocated) / 4)) {
-			cnt = -ENOMEM;
+	if (val != global_trace.entries) {
+		ret = ring_buffer_resize(global_trace.buffer, val);
+		if (ret < 0) {
+			cnt = ret;
 			goto out;
 		}
 
-		while (global_trace.entries < val) {
-			if (trace_alloc_page()) {
-				cnt = -ENOMEM;
-				goto out;
+		ret = ring_buffer_resize(max_tr.buffer, val);
+		if (ret < 0) {
+			int r;
+			cnt = ret;
+			r = ring_buffer_resize(global_trace.buffer,
+					       global_trace.entries);
+			if (r < 0) {
+				/* AARGH! We are left with different
+				 * size max buffer!!!! */
+				WARN_ON(1);
+				tracing_disabled = 1;
 			}
-			/* double check that we don't go over the known pages */
-			if (tracing_pages_allocated > pages_requested)
-				break;
+			goto out;
 		}
 
-	} else {
-		/* include the number of entries in val (inc of page entries) */
-		while (global_trace.entries > val + (ENTRIES_PER_PAGE - 1))
-			trace_free_page();
+		global_trace.entries = val;
 	}
 
-	/* check integrity */
-	for_each_tracing_cpu(i)
-		check_pages(global_trace.data[i]);
-
 	filp->f_pos += cnt;
 
 	/* If check pages failed, return ENOMEM */
@@ -2769,6 +2732,52 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 	return cnt;
 }
 
+static int mark_printk(const char *fmt, ...)
+{
+	int ret;
+	va_list args;
+	va_start(args, fmt);
+	ret = trace_vprintk(0, fmt, args);
+	va_end(args);
+	return ret;
+}
+
+static ssize_t
+tracing_mark_write(struct file *filp, const char __user *ubuf,
+					size_t cnt, loff_t *fpos)
+{
+	char *buf;
+	char *end;
+	struct trace_array *tr = &global_trace;
+
+	if (!tr->ctrl || tracing_disabled)
+		return -EINVAL;
+
+	if (cnt > TRACE_BUF_SIZE)
+		cnt = TRACE_BUF_SIZE;
+
+	buf = kmalloc(cnt + 1, GFP_KERNEL);
+	if (buf == NULL)
+		return -ENOMEM;
+
+	if (copy_from_user(buf, ubuf, cnt)) {
+		kfree(buf);
+		return -EFAULT;
+	}
+
+	/* Cut from the first nil or newline. */
+	buf[cnt] = '\0';
+	end = strchr(buf, '\n');
+	if (end)
+		*end = '\0';
+
+	cnt = mark_printk("%s\n", buf);
+	kfree(buf);
+	*fpos += cnt;
+
+	return cnt;
+}
+
 static struct file_operations tracing_max_lat_fops = {
 	.open		= tracing_open_generic,
 	.read		= tracing_max_lat_read,
@@ -2800,6 +2809,11 @@ static struct file_operations tracing_entries_fops = {
 	.write		= tracing_entries_write,
 };
 
+static struct file_operations tracing_mark_fops = {
+	.open		= tracing_open_generic,
+	.write		= tracing_mark_write,
+};
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 
 static ssize_t
@@ -2846,7 +2860,7 @@ struct dentry *tracing_init_dentry(void)
 #include "trace_selftest.c"
 #endif
 
-static __init void tracer_init_debugfs(void)
+static __init int tracer_init_debugfs(void)
 {
 	struct dentry *d_tracer;
 	struct dentry *entry;
@@ -2881,12 +2895,12 @@ static __init void tracer_init_debugfs(void)
 	entry = debugfs_create_file("available_tracers", 0444, d_tracer,
 				    &global_trace, &show_traces_fops);
 	if (!entry)
-		pr_warning("Could not create debugfs 'trace' entry\n");
+		pr_warning("Could not create debugfs 'available_tracers' entry\n");
 
 	entry = debugfs_create_file("current_tracer", 0444, d_tracer,
 				    &global_trace, &set_tracer_fops);
 	if (!entry)
-		pr_warning("Could not create debugfs 'trace' entry\n");
+		pr_warning("Could not create debugfs 'current_tracer' entry\n");
 
 	entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer,
 				    &tracing_max_latency,
@@ -2899,7 +2913,7 @@ static __init void tracer_init_debugfs(void)
 				    &tracing_thresh, &tracing_max_lat_fops);
 	if (!entry)
 		pr_warning("Could not create debugfs "
-			   "'tracing_threash' entry\n");
+			   "'tracing_thresh' entry\n");
 	entry = debugfs_create_file("README", 0644, d_tracer,
 				    NULL, &tracing_readme_fops);
 	if (!entry)
@@ -2909,13 +2923,19 @@ static __init void tracer_init_debugfs(void)
 				    NULL, &tracing_pipe_fops);
 	if (!entry)
 		pr_warning("Could not create debugfs "
-			   "'tracing_threash' entry\n");
+			   "'trace_pipe' entry\n");
 
 	entry = debugfs_create_file("trace_entries", 0644, d_tracer,
 				    &global_trace, &tracing_entries_fops);
 	if (!entry)
 		pr_warning("Could not create debugfs "
-			   "'tracing_threash' entry\n");
+			   "'trace_entries' entry\n");
+
+	entry = debugfs_create_file("trace_marker", 0220, d_tracer,
+				    NULL, &tracing_mark_fops);
+	if (!entry)
+		pr_warning("Could not create debugfs "
+			   "'trace_marker' entry\n");
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 	entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
@@ -2928,230 +2948,263 @@ static __init void tracer_init_debugfs(void)
 #ifdef CONFIG_SYSPROF_TRACER
 	init_tracer_sysprof_debugfs(d_tracer);
 #endif
+	return 0;
 }
 
-static int trace_alloc_page(void)
+int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 {
+	static DEFINE_SPINLOCK(trace_buf_lock);
+	static char trace_buf[TRACE_BUF_SIZE];
+
+	struct ring_buffer_event *event;
+	struct trace_array *tr = &global_trace;
 	struct trace_array_cpu *data;
-	struct page *page, *tmp;
-	LIST_HEAD(pages);
-	void *array;
-	unsigned pages_allocated = 0;
-	int i;
+	struct print_entry *entry;
+	unsigned long flags, irq_flags;
+	int cpu, len = 0, size, pc;
 
-	/* first allocate a page for each CPU */
-	for_each_tracing_cpu(i) {
-		array = (void *)__get_free_page(GFP_KERNEL);
-		if (array == NULL) {
-			printk(KERN_ERR "tracer: failed to allocate page"
-			       "for trace buffer!\n");
-			goto free_pages;
-		}
+	if (!tr->ctrl || tracing_disabled)
+		return 0;
 
-		pages_allocated++;
-		page = virt_to_page(array);
-		list_add(&page->lru, &pages);
+	pc = preempt_count();
+	preempt_disable_notrace();
+	cpu = raw_smp_processor_id();
+	data = tr->data[cpu];
 
-/* Only allocate if we are actually using the max trace */
-#ifdef CONFIG_TRACER_MAX_TRACE
-		array = (void *)__get_free_page(GFP_KERNEL);
-		if (array == NULL) {
-			printk(KERN_ERR "tracer: failed to allocate page"
-			       "for trace buffer!\n");
-			goto free_pages;
-		}
-		pages_allocated++;
-		page = virt_to_page(array);
-		list_add(&page->lru, &pages);
-#endif
-	}
+	if (unlikely(atomic_read(&data->disabled)))
+		goto out;
 
-	/* Now that we successfully allocate a page per CPU, add them */
-	for_each_tracing_cpu(i) {
-		data = global_trace.data[i];
-		page = list_entry(pages.next, struct page, lru);
-		list_del_init(&page->lru);
-		list_add_tail(&page->lru, &data->trace_pages);
-		ClearPageLRU(page);
+	spin_lock_irqsave(&trace_buf_lock, flags);
+	len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-		data = max_tr.data[i];
-		page = list_entry(pages.next, struct page, lru);
-		list_del_init(&page->lru);
-		list_add_tail(&page->lru, &data->trace_pages);
-		SetPageLRU(page);
-#endif
-	}
-	tracing_pages_allocated += pages_allocated;
-	global_trace.entries += ENTRIES_PER_PAGE;
+	len = min(len, TRACE_BUF_SIZE-1);
+	trace_buf[len] = 0;
 
-	return 0;
+	size = sizeof(*entry) + len + 1;
+	event = ring_buffer_lock_reserve(tr->buffer, size, &irq_flags);
+	if (!event)
+		goto out_unlock;
+	entry = ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, flags, pc);
+	entry->ent.type			= TRACE_PRINT;
+	entry->ip			= ip;
 
- free_pages:
-	list_for_each_entry_safe(page, tmp, &pages, lru) {
-		list_del_init(&page->lru);
-		__free_page(page);
-	}
-	return -ENOMEM;
+	memcpy(&entry->buf, trace_buf, len);
+	entry->buf[len] = 0;
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+ out_unlock:
+	spin_unlock_irqrestore(&trace_buf_lock, flags);
+
+ out:
+	preempt_enable_notrace();
+
+	return len;
 }
+EXPORT_SYMBOL_GPL(trace_vprintk);
 
-static int trace_free_page(void)
+int __ftrace_printk(unsigned long ip, const char *fmt, ...)
 {
-	struct trace_array_cpu *data;
-	struct page *page;
-	struct list_head *p;
-	int i;
-	int ret = 0;
+	int ret;
+	va_list ap;
 
-	/* free one page from each buffer */
-	for_each_tracing_cpu(i) {
-		data = global_trace.data[i];
-		p = data->trace_pages.next;
-		if (p == &data->trace_pages) {
-			/* should never happen */
-			WARN_ON(1);
-			tracing_disabled = 1;
-			ret = -1;
-			break;
-		}
-		page = list_entry(p, struct page, lru);
-		ClearPageLRU(page);
-		list_del(&page->lru);
-		tracing_pages_allocated--;
-		tracing_pages_allocated--;
-		__free_page(page);
+	if (!(trace_flags & TRACE_ITER_PRINTK))
+		return 0;
 
-		tracing_reset(data);
+	va_start(ap, fmt);
+	ret = trace_vprintk(ip, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__ftrace_printk);
 
-#ifdef CONFIG_TRACER_MAX_TRACE
-		data = max_tr.data[i];
-		p = data->trace_pages.next;
-		if (p == &data->trace_pages) {
-			/* should never happen */
-			WARN_ON(1);
-			tracing_disabled = 1;
-			ret = -1;
-			break;
-		}
-		page = list_entry(p, struct page, lru);
-		ClearPageLRU(page);
-		list_del(&page->lru);
-		__free_page(page);
+static int trace_panic_handler(struct notifier_block *this,
+			       unsigned long event, void *unused)
+{
+	ftrace_dump();
+	return NOTIFY_OK;
+}
 
-		tracing_reset(data);
-#endif
-	}
-	global_trace.entries -= ENTRIES_PER_PAGE;
+static struct notifier_block trace_panic_notifier = {
+	.notifier_call  = trace_panic_handler,
+	.next           = NULL,
+	.priority       = 150   /* priority: INT_MAX >= x >= 0 */
+};
 
-	return ret;
+static int trace_die_handler(struct notifier_block *self,
+			     unsigned long val,
+			     void *data)
+{
+	switch (val) {
+	case DIE_OOPS:
+		ftrace_dump();
+		break;
+	default:
+		break;
+	}
+	return NOTIFY_OK;
 }
 
-__init static int tracer_alloc_buffers(void)
+static struct notifier_block trace_die_notifier = {
+	.notifier_call = trace_die_handler,
+	.priority = 200
+};
+
+/*
+ * printk is set to max of 1024, we really don't need it that big.
+ * Nothing should be printing 1000 characters anyway.
+ */
+#define TRACE_MAX_PRINT		1000
+
+/*
+ * Define here KERN_TRACE so that we have one place to modify
+ * it if we decide to change what log level the ftrace dump
+ * should be at.
+ */
+#define KERN_TRACE		KERN_INFO
+
+static void
+trace_printk_seq(struct trace_seq *s)
 {
-	struct trace_array_cpu *data;
-	void *array;
-	struct page *page;
-	int pages = 0;
-	int ret = -ENOMEM;
-	int i;
+	/* Probably should print a warning here. */
+	if (s->len >= 1000)
+		s->len = 1000;
 
-	/* TODO: make the number of buffers hot pluggable with CPUS */
-	tracing_nr_buffers = num_possible_cpus();
-	tracing_buffer_mask = cpu_possible_map;
+	/* should be zero ended, but we are paranoid. */
+	s->buffer[s->len] = 0;
 
-	/* Allocate the first page for all buffers */
-	for_each_tracing_cpu(i) {
-		data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
-		max_tr.data[i] = &per_cpu(max_data, i);
+	printk(KERN_TRACE "%s", s->buffer);
 
-		array = (void *)__get_free_page(GFP_KERNEL);
-		if (array == NULL) {
-			printk(KERN_ERR "tracer: failed to allocate page"
-			       "for trace buffer!\n");
-			goto free_buffers;
-		}
+	trace_seq_reset(s);
+}
+
+
+void ftrace_dump(void)
+{
+	static DEFINE_SPINLOCK(ftrace_dump_lock);
+	/* use static because iter can be a bit big for the stack */
+	static struct trace_iterator iter;
+	static cpumask_t mask;
+	static int dump_ran;
+	unsigned long flags;
+	int cnt = 0, cpu;
 
-		/* set the array to the list */
-		INIT_LIST_HEAD(&data->trace_pages);
-		page = virt_to_page(array);
-		list_add(&page->lru, &data->trace_pages);
-		/* use the LRU flag to differentiate the two buffers */
-		ClearPageLRU(page);
+	/* only one dump */
+	spin_lock_irqsave(&ftrace_dump_lock, flags);
+	if (dump_ran)
+		goto out;
 
-		data->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
-		max_tr.data[i]->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+	dump_ran = 1;
 
-/* Only allocate if we are actually using the max trace */
-#ifdef CONFIG_TRACER_MAX_TRACE
-		array = (void *)__get_free_page(GFP_KERNEL);
-		if (array == NULL) {
-			printk(KERN_ERR "tracer: failed to allocate page"
-			       "for trace buffer!\n");
-			goto free_buffers;
-		}
+	/* No turning back! */
+	ftrace_kill_atomic();
 
-		INIT_LIST_HEAD(&max_tr.data[i]->trace_pages);
-		page = virt_to_page(array);
-		list_add(&page->lru, &max_tr.data[i]->trace_pages);
-		SetPageLRU(page);
-#endif
+	for_each_tracing_cpu(cpu) {
+		atomic_inc(&global_trace.data[cpu]->disabled);
 	}
 
+	printk(KERN_TRACE "Dumping ftrace buffer:\n");
+
+	iter.tr = &global_trace;
+	iter.trace = current_trace;
+
 	/*
-	 * Since we allocate by orders of pages, we may be able to
-	 * round up a bit.
+	 * We need to stop all tracing on all CPUS to read the
+	 * the next buffer. This is a bit expensive, but is
+	 * not done often. We fill all what we can read,
+	 * and then release the locks again.
 	 */
-	global_trace.entries = ENTRIES_PER_PAGE;
-	pages++;
 
-	while (global_trace.entries < trace_nr_entries) {
-		if (trace_alloc_page())
-			break;
-		pages++;
+	cpus_clear(mask);
+
+	while (!trace_empty(&iter)) {
+
+		if (!cnt)
+			printk(KERN_TRACE "---------------------------------\n");
+
+		cnt++;
+
+		/* reset all but tr, trace, and overruns */
+		memset(&iter.seq, 0,
+		       sizeof(struct trace_iterator) -
+		       offsetof(struct trace_iterator, seq));
+		iter.iter_flags |= TRACE_FILE_LAT_FMT;
+		iter.pos = -1;
+
+		if (find_next_entry_inc(&iter) != NULL) {
+			print_trace_line(&iter);
+			trace_consume(&iter);
+		}
+
+		trace_printk_seq(&iter.seq);
 	}
-	max_tr.entries = global_trace.entries;
 
-	pr_info("tracer: %d pages allocated for %ld entries of %ld bytes\n",
-		pages, trace_nr_entries, (long)TRACE_ENTRY_SIZE);
-	pr_info("   actual entries %ld\n", global_trace.entries);
+	if (!cnt)
+		printk(KERN_TRACE "   (ftrace buffer empty)\n");
+	else
+		printk(KERN_TRACE "---------------------------------\n");
+
+ out:
+	spin_unlock_irqrestore(&ftrace_dump_lock, flags);
+}
+
+__init static int tracer_alloc_buffers(void)
+{
+	struct trace_array_cpu *data;
+	int i;
+
+	/* TODO: make the number of buffers hot pluggable with CPUS */
+	tracing_buffer_mask = cpu_possible_map;
+
+	global_trace.buffer = ring_buffer_alloc(trace_buf_size,
+						   TRACE_BUFFER_FLAGS);
+	if (!global_trace.buffer) {
+		printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
+		WARN_ON(1);
+		return 0;
+	}
+	global_trace.entries = ring_buffer_size(global_trace.buffer);
 
-	tracer_init_debugfs();
+#ifdef CONFIG_TRACER_MAX_TRACE
+	max_tr.buffer = ring_buffer_alloc(trace_buf_size,
+					     TRACE_BUFFER_FLAGS);
+	if (!max_tr.buffer) {
+		printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n");
+		WARN_ON(1);
+		ring_buffer_free(global_trace.buffer);
+		return 0;
+	}
+	max_tr.entries = ring_buffer_size(max_tr.buffer);
+	WARN_ON(max_tr.entries != global_trace.entries);
+#endif
+
+	/* Allocate the first page for all buffers */
+	for_each_tracing_cpu(i) {
+		data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
+		max_tr.data[i] = &per_cpu(max_data, i);
+	}
 
 	trace_init_cmdlines();
 
-	register_tracer(&no_tracer);
-	current_trace = &no_tracer;
+	register_tracer(&nop_trace);
+#ifdef CONFIG_BOOT_TRACER
+	register_tracer(&boot_tracer);
+	current_trace = &boot_tracer;
+	current_trace->init(&global_trace);
+#else
+	current_trace = &nop_trace;
+#endif
 
 	/* All seems OK, enable tracing */
 	global_trace.ctrl = tracer_enabled;
 	tracing_disabled = 0;
 
-	return 0;
+	atomic_notifier_chain_register(&panic_notifier_list,
+				       &trace_panic_notifier);
 
- free_buffers:
-	for (i-- ; i >= 0; i--) {
-		struct page *page, *tmp;
-		struct trace_array_cpu *data = global_trace.data[i];
+	register_die_notifier(&trace_die_notifier);
 
-		if (data) {
-			list_for_each_entry_safe(page, tmp,
-						 &data->trace_pages, lru) {
-				list_del_init(&page->lru);
-				__free_page(page);
-			}
-		}
-
-#ifdef CONFIG_TRACER_MAX_TRACE
-		data = max_tr.data[i];
-		if (data) {
-			list_for_each_entry_safe(page, tmp,
-						 &data->trace_pages, lru) {
-				list_del_init(&page->lru);
-				__free_page(page);
-			}
-		}
-#endif
-	}
-	return ret;
+	return 0;
 }
-fs_initcall(tracer_alloc_buffers);
+early_initcall(tracer_alloc_buffers);
+fs_initcall(tracer_init_debugfs);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index f69f867..f1f9957 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -5,7 +5,9 @@
 #include <asm/atomic.h>
 #include <linux/sched.h>
 #include <linux/clocksource.h>
+#include <linux/ring_buffer.h>
 #include <linux/mmiotrace.h>
+#include <linux/ftrace.h>
 
 enum trace_type {
 	__TRACE_FIRST_TYPE = 0,
@@ -13,38 +15,60 @@ enum trace_type {
 	TRACE_FN,
 	TRACE_CTX,
 	TRACE_WAKE,
+	TRACE_CONT,
 	TRACE_STACK,
+	TRACE_PRINT,
 	TRACE_SPECIAL,
 	TRACE_MMIO_RW,
 	TRACE_MMIO_MAP,
+	TRACE_BOOT,
 
 	__TRACE_LAST_TYPE
 };
 
 /*
+ * The trace entry - the most basic unit of tracing. This is what
+ * is printed in the end as a single line in the trace output, such as:
+ *
+ *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
+ */
+struct trace_entry {
+	unsigned char		type;
+	unsigned char		cpu;
+	unsigned char		flags;
+	unsigned char		preempt_count;
+	int			pid;
+};
+
+/*
  * Function trace entry - function address and parent function addres:
  */
 struct ftrace_entry {
+	struct trace_entry	ent;
 	unsigned long		ip;
 	unsigned long		parent_ip;
 };
+extern struct tracer boot_tracer;
 
 /*
  * Context switch trace entry - which task (and prio) we switched from/to:
  */
 struct ctx_switch_entry {
+	struct trace_entry	ent;
 	unsigned int		prev_pid;
 	unsigned char		prev_prio;
 	unsigned char		prev_state;
 	unsigned int		next_pid;
 	unsigned char		next_prio;
 	unsigned char		next_state;
+	unsigned int		next_cpu;
 };
 
 /*
  * Special (free-form) trace entry:
  */
 struct special_entry {
+	struct trace_entry	ent;
 	unsigned long		arg1;
 	unsigned long		arg2;
 	unsigned long		arg3;
@@ -57,33 +81,60 @@ struct special_entry {
 #define FTRACE_STACK_ENTRIES	8
 
 struct stack_entry {
+	struct trace_entry	ent;
 	unsigned long		caller[FTRACE_STACK_ENTRIES];
 };
 
 /*
- * The trace entry - the most basic unit of tracing. This is what
- * is printed in the end as a single line in the trace output, such as:
- *
- *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
+ * ftrace_printk entry:
  */
-struct trace_entry {
-	char			type;
-	char			cpu;
-	char			flags;
-	char			preempt_count;
-	int			pid;
-	cycle_t			t;
-	union {
-		struct ftrace_entry		fn;
-		struct ctx_switch_entry		ctx;
-		struct special_entry		special;
-		struct stack_entry		stack;
-		struct mmiotrace_rw		mmiorw;
-		struct mmiotrace_map		mmiomap;
-	};
+struct print_entry {
+	struct trace_entry	ent;
+	unsigned long		ip;
+	char			buf[];
+};
+
+#define TRACE_OLD_SIZE		88
+
+struct trace_field_cont {
+	unsigned char		type;
+	/* Temporary till we get rid of this completely */
+	char			buf[TRACE_OLD_SIZE - 1];
+};
+
+struct trace_mmiotrace_rw {
+	struct trace_entry	ent;
+	struct mmiotrace_rw	rw;
 };
 
-#define TRACE_ENTRY_SIZE	sizeof(struct trace_entry)
+struct trace_mmiotrace_map {
+	struct trace_entry	ent;
+	struct mmiotrace_map	map;
+};
+
+struct trace_boot {
+	struct trace_entry	ent;
+	struct boot_trace	initcall;
+};
+
+/*
+ * trace_flag_type is an enumeration that holds different
+ * states when a trace occurs. These are:
+ *  IRQS_OFF	- interrupts were disabled
+ *  NEED_RESCED - reschedule is requested
+ *  HARDIRQ	- inside an interrupt handler
+ *  SOFTIRQ	- inside a softirq handler
+ *  CONT	- multiple entries hold the trace item
+ */
+enum trace_flag_type {
+	TRACE_FLAG_IRQS_OFF		= 0x01,
+	TRACE_FLAG_NEED_RESCHED		= 0x02,
+	TRACE_FLAG_HARDIRQ		= 0x04,
+	TRACE_FLAG_SOFTIRQ		= 0x08,
+	TRACE_FLAG_CONT			= 0x10,
+};
+
+#define TRACE_BUF_SIZE		1024
 
 /*
  * The CPU trace array - it consists of thousands of trace entries
@@ -91,16 +142,9 @@ struct trace_entry {
  * the trace, etc.)
  */
 struct trace_array_cpu {
-	struct list_head	trace_pages;
 	atomic_t		disabled;
-	raw_spinlock_t		lock;
-	struct lock_class_key	lock_key;
 
 	/* these fields get copied into max-trace: */
-	unsigned		trace_head_idx;
-	unsigned		trace_tail_idx;
-	void			*trace_head; /* producer */
-	void			*trace_tail; /* consumer */
 	unsigned long		trace_idx;
 	unsigned long		overrun;
 	unsigned long		saved_latency;
@@ -124,6 +168,7 @@ struct trace_iterator;
  * They have on/off state as well:
  */
 struct trace_array {
+	struct ring_buffer	*buffer;
 	unsigned long		entries;
 	long			ctrl;
 	int			cpu;
@@ -132,6 +177,56 @@ struct trace_array {
 	struct trace_array_cpu	*data[NR_CPUS];
 };
 
+#define FTRACE_CMP_TYPE(var, type) \
+	__builtin_types_compatible_p(typeof(var), type *)
+
+#undef IF_ASSIGN
+#define IF_ASSIGN(var, entry, etype, id)		\
+	if (FTRACE_CMP_TYPE(var, etype)) {		\
+		var = (typeof(var))(entry);		\
+		WARN_ON(id && (entry)->type != id);	\
+		break;					\
+	}
+
+/* Will cause compile errors if type is not found. */
+extern void __ftrace_bad_type(void);
+
+/*
+ * The trace_assign_type is a verifier that the entry type is
+ * the same as the type being assigned. To add new types simply
+ * add a line with the following format:
+ *
+ * IF_ASSIGN(var, ent, type, id);
+ *
+ *  Where "type" is the trace type that includes the trace_entry
+ *  as the "ent" item. And "id" is the trace identifier that is
+ *  used in the trace_type enum.
+ *
+ *  If the type can have more than one id, then use zero.
+ */
+#define trace_assign_type(var, ent)					\
+	do {								\
+		IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN);	\
+		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
+		IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
+		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
+		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
+		IF_ASSIGN(var, ent, struct special_entry, 0);		\
+		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
+			  TRACE_MMIO_RW);				\
+		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
+			  TRACE_MMIO_MAP);				\
+		IF_ASSIGN(var, ent, struct trace_boot, TRACE_BOOT);	\
+		__ftrace_bad_type();					\
+	} while (0)
+
+/* Return values for print_line callback */
+enum print_line_t {
+	TRACE_TYPE_PARTIAL_LINE	= 0,	/* Retry after flushing the seq */
+	TRACE_TYPE_HANDLED	= 1,
+	TRACE_TYPE_UNHANDLED	= 2	/* Relay to other output functions */
+};
+
 /*
  * A specific tracer, represented by methods that operate on a trace array:
  */
@@ -152,7 +247,7 @@ struct tracer {
 	int			(*selftest)(struct tracer *trace,
 					    struct trace_array *tr);
 #endif
-	int			(*print_line)(struct trace_iterator *iter);
+	enum print_line_t	(*print_line)(struct trace_iterator *iter);
 	struct tracer		*next;
 	int			print_max;
 };
@@ -171,57 +266,58 @@ struct trace_iterator {
 	struct trace_array	*tr;
 	struct tracer		*trace;
 	void			*private;
-	long			last_overrun[NR_CPUS];
-	long			overrun[NR_CPUS];
+	struct ring_buffer_iter	*buffer_iter[NR_CPUS];
 
 	/* The below is zeroed out in pipe_read */
 	struct trace_seq	seq;
 	struct trace_entry	*ent;
 	int			cpu;
-
-	struct trace_entry	*prev_ent;
-	int			prev_cpu;
+	u64			ts;
 
 	unsigned long		iter_flags;
 	loff_t			pos;
-	unsigned long		next_idx[NR_CPUS];
-	struct list_head	*next_page[NR_CPUS];
-	unsigned		next_page_idx[NR_CPUS];
 	long			idx;
 };
 
-void tracing_reset(struct trace_array_cpu *data);
+void trace_wake_up(void);
+void tracing_reset(struct trace_array *tr, int cpu);
 int tracing_open_generic(struct inode *inode, struct file *filp);
 struct dentry *tracing_init_dentry(void);
 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 
+struct trace_entry *tracing_get_trace_entry(struct trace_array *tr,
+						struct trace_array_cpu *data);
+void tracing_generic_entry_update(struct trace_entry *entry,
+				  unsigned long flags,
+				  int pc);
+
 void ftrace(struct trace_array *tr,
 			    struct trace_array_cpu *data,
 			    unsigned long ip,
 			    unsigned long parent_ip,
-			    unsigned long flags);
+			    unsigned long flags, int pc);
 void tracing_sched_switch_trace(struct trace_array *tr,
 				struct trace_array_cpu *data,
 				struct task_struct *prev,
 				struct task_struct *next,
-				unsigned long flags);
+				unsigned long flags, int pc);
 void tracing_record_cmdline(struct task_struct *tsk);
 
 void tracing_sched_wakeup_trace(struct trace_array *tr,
 				struct trace_array_cpu *data,
 				struct task_struct *wakee,
 				struct task_struct *cur,
-				unsigned long flags);
+				unsigned long flags, int pc);
 void trace_special(struct trace_array *tr,
 		   struct trace_array_cpu *data,
 		   unsigned long arg1,
 		   unsigned long arg2,
-		   unsigned long arg3);
+		   unsigned long arg3, int pc);
 void trace_function(struct trace_array *tr,
 		    struct trace_array_cpu *data,
 		    unsigned long ip,
 		    unsigned long parent_ip,
-		    unsigned long flags);
+		    unsigned long flags, int pc);
 
 void tracing_start_cmdline_record(void);
 void tracing_stop_cmdline_record(void);
@@ -268,51 +364,33 @@ extern unsigned long ftrace_update_tot_cnt;
 extern int DYN_FTRACE_TEST_NAME(void);
 #endif
 
-#ifdef CONFIG_MMIOTRACE
-extern void __trace_mmiotrace_rw(struct trace_array *tr,
-				struct trace_array_cpu *data,
-				struct mmiotrace_rw *rw);
-extern void __trace_mmiotrace_map(struct trace_array *tr,
-				struct trace_array_cpu *data,
-				struct mmiotrace_map *map);
-#endif
-
 #ifdef CONFIG_FTRACE_STARTUP_TEST
-#ifdef CONFIG_FTRACE
 extern int trace_selftest_startup_function(struct tracer *trace,
 					   struct trace_array *tr);
-#endif
-#ifdef CONFIG_IRQSOFF_TRACER
 extern int trace_selftest_startup_irqsoff(struct tracer *trace,
 					  struct trace_array *tr);
-#endif
-#ifdef CONFIG_PREEMPT_TRACER
 extern int trace_selftest_startup_preemptoff(struct tracer *trace,
 					     struct trace_array *tr);
-#endif
-#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER)
 extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace,
 						 struct trace_array *tr);
-#endif
-#ifdef CONFIG_SCHED_TRACER
 extern int trace_selftest_startup_wakeup(struct tracer *trace,
 					 struct trace_array *tr);
-#endif
-#ifdef CONFIG_CONTEXT_SWITCH_TRACER
+extern int trace_selftest_startup_nop(struct tracer *trace,
+					 struct trace_array *tr);
 extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 					       struct trace_array *tr);
-#endif
-#ifdef CONFIG_SYSPROF_TRACER
 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 					       struct trace_array *tr);
-#endif
 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 
 extern void *head_page(struct trace_array_cpu *data);
 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
+extern void trace_seq_print_cont(struct trace_seq *s,
+				 struct trace_iterator *iter);
 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
 				 size_t cnt);
 extern long ns2usecs(cycle_t nsec);
+extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
 
 extern unsigned long trace_flags;
 
@@ -334,6 +412,9 @@ enum trace_iterator_flags {
 	TRACE_ITER_BLOCK		= 0x80,
 	TRACE_ITER_STACKTRACE		= 0x100,
 	TRACE_ITER_SCHED_TREE		= 0x200,
+	TRACE_ITER_PRINTK		= 0x400,
 };
 
+extern struct tracer nop_trace;
+
 #endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
new file mode 100644
index 0000000..d0a5e50
--- /dev/null
+++ b/kernel/trace/trace_boot.c
@@ -0,0 +1,126 @@
+/*
+ * ring buffer based initcalls tracer
+ *
+ * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/debugfs.h>
+#include <linux/ftrace.h>
+#include <linux/kallsyms.h>
+
+#include "trace.h"
+
+static struct trace_array *boot_trace;
+static int trace_boot_enabled;
+
+
+/* Should be started after do_pre_smp_initcalls() in init/main.c */
+void start_boot_trace(void)
+{
+	trace_boot_enabled = 1;
+}
+
+void stop_boot_trace(void)
+{
+	trace_boot_enabled = 0;
+}
+
+void reset_boot_trace(struct trace_array *tr)
+{
+	stop_boot_trace();
+}
+
+static void boot_trace_init(struct trace_array *tr)
+{
+	int cpu;
+	boot_trace = tr;
+
+	trace_boot_enabled = 0;
+
+	for_each_cpu_mask(cpu, cpu_possible_map)
+		tracing_reset(tr, cpu);
+}
+
+static void boot_trace_ctrl_update(struct trace_array *tr)
+{
+	if (tr->ctrl)
+		start_boot_trace();
+	else
+		stop_boot_trace();
+}
+
+static enum print_line_t initcall_print_line(struct trace_iterator *iter)
+{
+	int ret;
+	struct trace_entry *entry = iter->ent;
+	struct trace_boot *field = (struct trace_boot *)entry;
+	struct boot_trace *it = &field->initcall;
+	struct trace_seq *s = &iter->seq;
+	struct timespec calltime = ktime_to_timespec(it->calltime);
+	struct timespec rettime = ktime_to_timespec(it->rettime);
+
+	if (entry->type == TRACE_BOOT) {
+		ret = trace_seq_printf(s, "[%5ld.%09ld] calling  %s @ %i\n",
+					  calltime.tv_sec,
+					  calltime.tv_nsec,
+					  it->func, it->caller);
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+
+		ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s "
+					  "returned %d after %lld msecs\n",
+					  rettime.tv_sec,
+					  rettime.tv_nsec,
+					  it->func, it->result, it->duration);
+
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+		return TRACE_TYPE_HANDLED;
+	}
+	return TRACE_TYPE_UNHANDLED;
+}
+
+struct tracer boot_tracer __read_mostly =
+{
+	.name		= "initcall",
+	.init		= boot_trace_init,
+	.reset		= reset_boot_trace,
+	.ctrl_update	= boot_trace_ctrl_update,
+	.print_line	= initcall_print_line,
+};
+
+void trace_boot(struct boot_trace *it, initcall_t fn)
+{
+	struct ring_buffer_event *event;
+	struct trace_boot *entry;
+	struct trace_array_cpu *data;
+	unsigned long irq_flags;
+	struct trace_array *tr = boot_trace;
+
+	if (!trace_boot_enabled)
+		return;
+
+	/* Get its name now since this function could
+	 * disappear because it is in the .init section.
+	 */
+	sprint_symbol(it->func, (unsigned long)fn);
+	preempt_disable();
+	data = tr->data[smp_processor_id()];
+
+	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+					 &irq_flags);
+	if (!event)
+		goto out;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, 0, 0);
+	entry->ent.type = TRACE_BOOT;
+	entry->initcall = *it;
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+	trace_wake_up();
+
+ out:
+	preempt_enable();
+}
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 3121448..e90eb0c 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -23,7 +23,7 @@ static void function_reset(struct trace_array *tr)
 	tr->time_start = ftrace_now(tr->cpu);
 
 	for_each_online_cpu(cpu)
-		tracing_reset(tr->data[cpu]);
+		tracing_reset(tr, cpu);
 }
 
 static void start_function_trace(struct trace_array *tr)
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index ece6cfb..a7db7f0 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -95,7 +95,7 @@ irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip)
 	disabled = atomic_inc_return(&data->disabled);
 
 	if (likely(disabled == 1))
-		trace_function(tr, data, ip, parent_ip, flags);
+		trace_function(tr, data, ip, parent_ip, flags, preempt_count());
 
 	atomic_dec(&data->disabled);
 }
@@ -130,6 +130,7 @@ check_critical_timing(struct trace_array *tr,
 	unsigned long latency, t0, t1;
 	cycle_t T0, T1, delta;
 	unsigned long flags;
+	int pc;
 
 	/*
 	 * usecs conversion is slow so we try to delay the conversion
@@ -141,6 +142,8 @@ check_critical_timing(struct trace_array *tr,
 
 	local_save_flags(flags);
 
+	pc = preempt_count();
+
 	if (!report_latency(delta))
 		goto out;
 
@@ -150,7 +153,7 @@ check_critical_timing(struct trace_array *tr,
 	if (!report_latency(delta))
 		goto out_unlock;
 
-	trace_function(tr, data, CALLER_ADDR0, parent_ip, flags);
+	trace_function(tr, data, CALLER_ADDR0, parent_ip, flags, pc);
 
 	latency = nsecs_to_usecs(delta);
 
@@ -173,8 +176,8 @@ out_unlock:
 out:
 	data->critical_sequence = max_sequence;
 	data->preempt_timestamp = ftrace_now(cpu);
-	tracing_reset(data);
-	trace_function(tr, data, CALLER_ADDR0, parent_ip, flags);
+	tracing_reset(tr, cpu);
+	trace_function(tr, data, CALLER_ADDR0, parent_ip, flags, pc);
 }
 
 static inline void
@@ -203,11 +206,11 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip)
 	data->critical_sequence = max_sequence;
 	data->preempt_timestamp = ftrace_now(cpu);
 	data->critical_start = parent_ip ? : ip;
-	tracing_reset(data);
+	tracing_reset(tr, cpu);
 
 	local_save_flags(flags);
 
-	trace_function(tr, data, ip, parent_ip, flags);
+	trace_function(tr, data, ip, parent_ip, flags, preempt_count());
 
 	per_cpu(tracing_cpu, cpu) = 1;
 
@@ -234,14 +237,14 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip)
 
 	data = tr->data[cpu];
 
-	if (unlikely(!data) || unlikely(!head_page(data)) ||
+	if (unlikely(!data) ||
 	    !data->critical_start || atomic_read(&data->disabled))
 		return;
 
 	atomic_inc(&data->disabled);
 
 	local_save_flags(flags);
-	trace_function(tr, data, ip, parent_ip, flags);
+	trace_function(tr, data, ip, parent_ip, flags, preempt_count());
 	check_critical_timing(tr, data, parent_ip ? : ip, cpu);
 	data->critical_start = 0;
 	atomic_dec(&data->disabled);
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index b13dc19..f284846 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -27,7 +27,7 @@ static void mmio_reset_data(struct trace_array *tr)
 	tr->time_start = ftrace_now(tr->cpu);
 
 	for_each_online_cpu(cpu)
-		tracing_reset(tr->data[cpu]);
+		tracing_reset(tr, cpu);
 }
 
 static void mmio_trace_init(struct trace_array *tr)
@@ -130,10 +130,14 @@ static unsigned long count_overruns(struct trace_iterator *iter)
 {
 	int cpu;
 	unsigned long cnt = 0;
+/* FIXME: */
+#if 0
 	for_each_online_cpu(cpu) {
 		cnt += iter->overrun[cpu];
 		iter->overrun[cpu] = 0;
 	}
+#endif
+	(void)cpu;
 	return cnt;
 }
 
@@ -171,17 +175,21 @@ print_out:
 	return (ret == -EBUSY) ? 0 : ret;
 }
 
-static int mmio_print_rw(struct trace_iterator *iter)
+static enum print_line_t mmio_print_rw(struct trace_iterator *iter)
 {
 	struct trace_entry *entry = iter->ent;
-	struct mmiotrace_rw *rw	= &entry->mmiorw;
+	struct trace_mmiotrace_rw *field;
+	struct mmiotrace_rw *rw;
 	struct trace_seq *s	= &iter->seq;
-	unsigned long long t	= ns2usecs(entry->t);
+	unsigned long long t	= ns2usecs(iter->ts);
 	unsigned long usec_rem	= do_div(t, 1000000ULL);
 	unsigned secs		= (unsigned long)t;
 	int ret = 1;
 
-	switch (entry->mmiorw.opcode) {
+	trace_assign_type(field, entry);
+	rw = &field->rw;
+
+	switch (rw->opcode) {
 	case MMIO_READ:
 		ret = trace_seq_printf(s,
 			"R %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
@@ -209,21 +217,25 @@ static int mmio_print_rw(struct trace_iterator *iter)
 		break;
 	}
 	if (ret)
-		return 1;
-	return 0;
+		return TRACE_TYPE_HANDLED;
+	return TRACE_TYPE_PARTIAL_LINE;
 }
 
-static int mmio_print_map(struct trace_iterator *iter)
+static enum print_line_t mmio_print_map(struct trace_iterator *iter)
 {
 	struct trace_entry *entry = iter->ent;
-	struct mmiotrace_map *m	= &entry->mmiomap;
+	struct trace_mmiotrace_map *field;
+	struct mmiotrace_map *m;
 	struct trace_seq *s	= &iter->seq;
-	unsigned long long t	= ns2usecs(entry->t);
+	unsigned long long t	= ns2usecs(iter->ts);
 	unsigned long usec_rem	= do_div(t, 1000000ULL);
 	unsigned secs		= (unsigned long)t;
-	int ret = 1;
+	int ret;
 
-	switch (entry->mmiorw.opcode) {
+	trace_assign_type(field, entry);
+	m = &field->map;
+
+	switch (m->opcode) {
 	case MMIO_PROBE:
 		ret = trace_seq_printf(s,
 			"MAP %lu.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n",
@@ -241,20 +253,43 @@ static int mmio_print_map(struct trace_iterator *iter)
 		break;
 	}
 	if (ret)
-		return 1;
-	return 0;
+		return TRACE_TYPE_HANDLED;
+	return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static enum print_line_t mmio_print_mark(struct trace_iterator *iter)
+{
+	struct trace_entry *entry = iter->ent;
+	struct print_entry *print = (struct print_entry *)entry;
+	const char *msg		= print->buf;
+	struct trace_seq *s	= &iter->seq;
+	unsigned long long t	= ns2usecs(iter->ts);
+	unsigned long usec_rem	= do_div(t, 1000000ULL);
+	unsigned secs		= (unsigned long)t;
+	int ret;
+
+	/* The trailing newline must be in the message. */
+	ret = trace_seq_printf(s, "MARK %lu.%06lu %s", secs, usec_rem, msg);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	if (entry->flags & TRACE_FLAG_CONT)
+		trace_seq_print_cont(s, iter);
+
+	return TRACE_TYPE_HANDLED;
 }
 
-/* return 0 to abort printing without consuming current entry in pipe mode */
-static int mmio_print_line(struct trace_iterator *iter)
+static enum print_line_t mmio_print_line(struct trace_iterator *iter)
 {
 	switch (iter->ent->type) {
 	case TRACE_MMIO_RW:
 		return mmio_print_rw(iter);
 	case TRACE_MMIO_MAP:
 		return mmio_print_map(iter);
+	case TRACE_PRINT:
+		return mmio_print_mark(iter);
 	default:
-		return 1; /* ignore unknown entries */
+		return TRACE_TYPE_HANDLED; /* ignore unknown entries */
 	}
 }
 
@@ -276,6 +311,27 @@ __init static int init_mmio_trace(void)
 }
 device_initcall(init_mmio_trace);
 
+static void __trace_mmiotrace_rw(struct trace_array *tr,
+				struct trace_array_cpu *data,
+				struct mmiotrace_rw *rw)
+{
+	struct ring_buffer_event *event;
+	struct trace_mmiotrace_rw *entry;
+	unsigned long irq_flags;
+
+	event	= ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+					   &irq_flags);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, 0, preempt_count());
+	entry->ent.type			= TRACE_MMIO_RW;
+	entry->rw			= *rw;
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+	trace_wake_up();
+}
+
 void mmio_trace_rw(struct mmiotrace_rw *rw)
 {
 	struct trace_array *tr = mmio_trace_array;
@@ -283,6 +339,27 @@ void mmio_trace_rw(struct mmiotrace_rw *rw)
 	__trace_mmiotrace_rw(tr, data, rw);
 }
 
+static void __trace_mmiotrace_map(struct trace_array *tr,
+				struct trace_array_cpu *data,
+				struct mmiotrace_map *map)
+{
+	struct ring_buffer_event *event;
+	struct trace_mmiotrace_map *entry;
+	unsigned long irq_flags;
+
+	event	= ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+					   &irq_flags);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, 0, preempt_count());
+	entry->ent.type			= TRACE_MMIO_MAP;
+	entry->map			= *map;
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+	trace_wake_up();
+}
+
 void mmio_trace_mapping(struct mmiotrace_map *map)
 {
 	struct trace_array *tr = mmio_trace_array;
@@ -293,3 +370,8 @@ void mmio_trace_mapping(struct mmiotrace_map *map)
 	__trace_mmiotrace_map(tr, data, map);
 	preempt_enable();
 }
+
+int mmio_trace_printk(const char *fmt, va_list args)
+{
+	return trace_vprintk(0, fmt, args);
+}
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
new file mode 100644
index 0000000..4592b48
--- /dev/null
+++ b/kernel/trace/trace_nop.c
@@ -0,0 +1,64 @@
+/*
+ * nop tracer
+ *
+ * Copyright (C) 2008 Steven Noonan <steven@uplinklabs.net>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/ftrace.h>
+
+#include "trace.h"
+
+static struct trace_array	*ctx_trace;
+
+static void start_nop_trace(struct trace_array *tr)
+{
+	/* Nothing to do! */
+}
+
+static void stop_nop_trace(struct trace_array *tr)
+{
+	/* Nothing to do! */
+}
+
+static void nop_trace_init(struct trace_array *tr)
+{
+	int cpu;
+	ctx_trace = tr;
+
+	for_each_online_cpu(cpu)
+		tracing_reset(tr, cpu);
+
+	if (tr->ctrl)
+		start_nop_trace(tr);
+}
+
+static void nop_trace_reset(struct trace_array *tr)
+{
+	if (tr->ctrl)
+		stop_nop_trace(tr);
+}
+
+static void nop_trace_ctrl_update(struct trace_array *tr)
+{
+	/* When starting a new trace, reset the buffers */
+	if (tr->ctrl)
+		start_nop_trace(tr);
+	else
+		stop_nop_trace(tr);
+}
+
+struct tracer nop_trace __read_mostly =
+{
+	.name		= "nop",
+	.init		= nop_trace_init,
+	.reset		= nop_trace_reset,
+	.ctrl_update	= nop_trace_ctrl_update,
+#ifdef CONFIG_FTRACE_SELFTEST
+	.selftest	= trace_selftest_startup_nop,
+#endif
+};
+
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index cb817a2..b8f56be 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -9,8 +9,8 @@
 #include <linux/debugfs.h>
 #include <linux/kallsyms.h>
 #include <linux/uaccess.h>
-#include <linux/marker.h>
 #include <linux/ftrace.h>
+#include <trace/sched.h>
 
 #include "trace.h"
 
@@ -19,15 +19,16 @@ static int __read_mostly	tracer_enabled;
 static atomic_t			sched_ref;
 
 static void
-sched_switch_func(void *private, void *__rq, struct task_struct *prev,
+probe_sched_switch(struct rq *__rq, struct task_struct *prev,
 			struct task_struct *next)
 {
-	struct trace_array **ptr = private;
-	struct trace_array *tr = *ptr;
 	struct trace_array_cpu *data;
 	unsigned long flags;
-	long disabled;
 	int cpu;
+	int pc;
+
+	if (!atomic_read(&sched_ref))
+		return;
 
 	tracing_record_cmdline(prev);
 	tracing_record_cmdline(next);
@@ -35,97 +36,41 @@ sched_switch_func(void *private, void *__rq, struct task_struct *prev,
 	if (!tracer_enabled)
 		return;
 
+	pc = preempt_count();
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = tr->data[cpu];
-	disabled = atomic_inc_return(&data->disabled);
+	data = ctx_trace->data[cpu];
 
-	if (likely(disabled == 1))
-		tracing_sched_switch_trace(tr, data, prev, next, flags);
+	if (likely(!atomic_read(&data->disabled)))
+		tracing_sched_switch_trace(ctx_trace, data, prev, next, flags, pc);
 
-	atomic_dec(&data->disabled);
 	local_irq_restore(flags);
 }
 
-static notrace void
-sched_switch_callback(void *probe_data, void *call_data,
-		      const char *format, va_list *args)
-{
-	struct task_struct *prev;
-	struct task_struct *next;
-	struct rq *__rq;
-
-	if (!atomic_read(&sched_ref))
-		return;
-
-	/* skip prev_pid %d next_pid %d prev_state %ld */
-	(void)va_arg(*args, int);
-	(void)va_arg(*args, int);
-	(void)va_arg(*args, long);
-	__rq = va_arg(*args, typeof(__rq));
-	prev = va_arg(*args, typeof(prev));
-	next = va_arg(*args, typeof(next));
-
-	/*
-	 * If tracer_switch_func only points to the local
-	 * switch func, it still needs the ptr passed to it.
-	 */
-	sched_switch_func(probe_data, __rq, prev, next);
-}
-
 static void
-wakeup_func(void *private, void *__rq, struct task_struct *wakee, struct
-			task_struct *curr)
+probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee)
 {
-	struct trace_array **ptr = private;
-	struct trace_array *tr = *ptr;
 	struct trace_array_cpu *data;
 	unsigned long flags;
-	long disabled;
-	int cpu;
+	int cpu, pc;
 
-	if (!tracer_enabled)
+	if (!likely(tracer_enabled))
 		return;
 
-	tracing_record_cmdline(curr);
+	pc = preempt_count();
+	tracing_record_cmdline(current);
 
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
-	data = tr->data[cpu];
-	disabled = atomic_inc_return(&data->disabled);
+	data = ctx_trace->data[cpu];
 
-	if (likely(disabled == 1))
-		tracing_sched_wakeup_trace(tr, data, wakee, curr, flags);
+	if (likely(!atomic_read(&data->disabled)))
+		tracing_sched_wakeup_trace(ctx_trace, data, wakee, current,
+					   flags, pc);
 
-	atomic_dec(&data->disabled);
 	local_irq_restore(flags);
 }
 
-static notrace void
-wake_up_callback(void *probe_data, void *call_data,
-		 const char *format, va_list *args)
-{
-	struct task_struct *curr;
-	struct task_struct *task;
-	struct rq *__rq;
-
-	if (likely(!tracer_enabled))
-		return;
-
-	/* Skip pid %d state %ld */
-	(void)va_arg(*args, int);
-	(void)va_arg(*args, long);
-	/* now get the meat: "rq %p task %p rq->curr %p" */
-	__rq = va_arg(*args, typeof(__rq));
-	task = va_arg(*args, typeof(task));
-	curr = va_arg(*args, typeof(curr));
-
-	tracing_record_cmdline(task);
-	tracing_record_cmdline(curr);
-
-	wakeup_func(probe_data, __rq, task, curr);
-}
-
 static void sched_switch_reset(struct trace_array *tr)
 {
 	int cpu;
@@ -133,67 +78,47 @@ static void sched_switch_reset(struct trace_array *tr)
 	tr->time_start = ftrace_now(tr->cpu);
 
 	for_each_online_cpu(cpu)
-		tracing_reset(tr->data[cpu]);
+		tracing_reset(tr, cpu);
 }
 
 static int tracing_sched_register(void)
 {
 	int ret;
 
-	ret = marker_probe_register("kernel_sched_wakeup",
-			"pid %d state %ld ## rq %p task %p rq->curr %p",
-			wake_up_callback,
-			&ctx_trace);
+	ret = register_trace_sched_wakeup(probe_sched_wakeup);
 	if (ret) {
-		pr_info("wakeup trace: Couldn't add marker"
+		pr_info("wakeup trace: Couldn't activate tracepoint"
 			" probe to kernel_sched_wakeup\n");
 		return ret;
 	}
 
-	ret = marker_probe_register("kernel_sched_wakeup_new",
-			"pid %d state %ld ## rq %p task %p rq->curr %p",
-			wake_up_callback,
-			&ctx_trace);
+	ret = register_trace_sched_wakeup_new(probe_sched_wakeup);
 	if (ret) {
-		pr_info("wakeup trace: Couldn't add marker"
+		pr_info("wakeup trace: Couldn't activate tracepoint"
 			" probe to kernel_sched_wakeup_new\n");
 		goto fail_deprobe;
 	}
 
-	ret = marker_probe_register("kernel_sched_schedule",
-		"prev_pid %d next_pid %d prev_state %ld "
-		"## rq %p prev %p next %p",
-		sched_switch_callback,
-		&ctx_trace);
+	ret = register_trace_sched_switch(probe_sched_switch);
 	if (ret) {
-		pr_info("sched trace: Couldn't add marker"
+		pr_info("sched trace: Couldn't activate tracepoint"
 			" probe to kernel_sched_schedule\n");
 		goto fail_deprobe_wake_new;
 	}
 
 	return ret;
 fail_deprobe_wake_new:
-	marker_probe_unregister("kernel_sched_wakeup_new",
-				wake_up_callback,
-				&ctx_trace);
+	unregister_trace_sched_wakeup_new(probe_sched_wakeup);
 fail_deprobe:
-	marker_probe_unregister("kernel_sched_wakeup",
-				wake_up_callback,
-				&ctx_trace);
+	unregister_trace_sched_wakeup(probe_sched_wakeup);
 	return ret;
 }
 
 static void tracing_sched_unregister(void)
 {
-	marker_probe_unregister("kernel_sched_schedule",
-				sched_switch_callback,
-				&ctx_trace);
-	marker_probe_unregister("kernel_sched_wakeup_new",
-				wake_up_callback,
-				&ctx_trace);
-	marker_probe_unregister("kernel_sched_wakeup",
-				wake_up_callback,
-				&ctx_trace);
+	unregister_trace_sched_switch(probe_sched_switch);
+	unregister_trace_sched_wakeup_new(probe_sched_wakeup);
+	unregister_trace_sched_wakeup(probe_sched_wakeup);
 }
 
 static void tracing_start_sched_switch(void)
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index e303ccb..fe4a252 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -15,7 +15,7 @@
 #include <linux/kallsyms.h>
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
-#include <linux/marker.h>
+#include <trace/sched.h>
 
 #include "trace.h"
 
@@ -44,10 +44,12 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip)
 	long disabled;
 	int resched;
 	int cpu;
+	int pc;
 
 	if (likely(!wakeup_task))
 		return;
 
+	pc = preempt_count();
 	resched = need_resched();
 	preempt_disable_notrace();
 
@@ -70,7 +72,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip)
 	if (task_cpu(wakeup_task) != cpu)
 		goto unlock;
 
-	trace_function(tr, data, ip, parent_ip, flags);
+	trace_function(tr, data, ip, parent_ip, flags, pc);
 
  unlock:
 	__raw_spin_unlock(&wakeup_lock);
@@ -112,17 +114,18 @@ static int report_latency(cycle_t delta)
 }
 
 static void notrace
-wakeup_sched_switch(void *private, void *rq, struct task_struct *prev,
+probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev,
 	struct task_struct *next)
 {
 	unsigned long latency = 0, t0 = 0, t1 = 0;
-	struct trace_array **ptr = private;
-	struct trace_array *tr = *ptr;
 	struct trace_array_cpu *data;
 	cycle_t T0, T1, delta;
 	unsigned long flags;
 	long disabled;
 	int cpu;
+	int pc;
+
+	tracing_record_cmdline(prev);
 
 	if (unlikely(!tracer_enabled))
 		return;
@@ -139,12 +142,14 @@ wakeup_sched_switch(void *private, void *rq, struct task_struct *prev,
 	if (next != wakeup_task)
 		return;
 
+	pc = preempt_count();
+
 	/* The task we are waiting for is waking up */
-	data = tr->data[wakeup_cpu];
+	data = wakeup_trace->data[wakeup_cpu];
 
 	/* disable local data, not wakeup_cpu data */
 	cpu = raw_smp_processor_id();
-	disabled = atomic_inc_return(&tr->data[cpu]->disabled);
+	disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled);
 	if (likely(disabled != 1))
 		goto out;
 
@@ -155,7 +160,7 @@ wakeup_sched_switch(void *private, void *rq, struct task_struct *prev,
 	if (unlikely(!tracer_enabled || next != wakeup_task))
 		goto out_unlock;
 
-	trace_function(tr, data, CALLER_ADDR1, CALLER_ADDR2, flags);
+	trace_function(wakeup_trace, data, CALLER_ADDR1, CALLER_ADDR2, flags, pc);
 
 	/*
 	 * usecs conversion is slow so we try to delay the conversion
@@ -174,39 +179,14 @@ wakeup_sched_switch(void *private, void *rq, struct task_struct *prev,
 	t0 = nsecs_to_usecs(T0);
 	t1 = nsecs_to_usecs(T1);
 
-	update_max_tr(tr, wakeup_task, wakeup_cpu);
+	update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu);
 
 out_unlock:
-	__wakeup_reset(tr);
+	__wakeup_reset(wakeup_trace);
 	__raw_spin_unlock(&wakeup_lock);
 	local_irq_restore(flags);
 out:
-	atomic_dec(&tr->data[cpu]->disabled);
-}
-
-static notrace void
-sched_switch_callback(void *probe_data, void *call_data,
-		      const char *format, va_list *args)
-{
-	struct task_struct *prev;
-	struct task_struct *next;
-	struct rq *__rq;
-
-	/* skip prev_pid %d next_pid %d prev_state %ld */
-	(void)va_arg(*args, int);
-	(void)va_arg(*args, int);
-	(void)va_arg(*args, long);
-	__rq = va_arg(*args, typeof(__rq));
-	prev = va_arg(*args, typeof(prev));
-	next = va_arg(*args, typeof(next));
-
-	tracing_record_cmdline(prev);
-
-	/*
-	 * If tracer_switch_func only points to the local
-	 * switch func, it still needs the ptr passed to it.
-	 */
-	wakeup_sched_switch(probe_data, __rq, prev, next);
+	atomic_dec(&wakeup_trace->data[cpu]->disabled);
 }
 
 static void __wakeup_reset(struct trace_array *tr)
@@ -216,7 +196,7 @@ static void __wakeup_reset(struct trace_array *tr)
 
 	for_each_possible_cpu(cpu) {
 		data = tr->data[cpu];
-		tracing_reset(data);
+		tracing_reset(tr, cpu);
 	}
 
 	wakeup_cpu = -1;
@@ -240,19 +220,26 @@ static void wakeup_reset(struct trace_array *tr)
 }
 
 static void
-wakeup_check_start(struct trace_array *tr, struct task_struct *p,
-		   struct task_struct *curr)
+probe_wakeup(struct rq *rq, struct task_struct *p)
 {
 	int cpu = smp_processor_id();
 	unsigned long flags;
 	long disabled;
+	int pc;
+
+	if (likely(!tracer_enabled))
+		return;
+
+	tracing_record_cmdline(p);
+	tracing_record_cmdline(current);
 
 	if (likely(!rt_task(p)) ||
 			p->prio >= wakeup_prio ||
-			p->prio >= curr->prio)
+			p->prio >= current->prio)
 		return;
 
-	disabled = atomic_inc_return(&tr->data[cpu]->disabled);
+	pc = preempt_count();
+	disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled);
 	if (unlikely(disabled != 1))
 		goto out;
 
@@ -264,7 +251,7 @@ wakeup_check_start(struct trace_array *tr, struct task_struct *p,
 		goto out_locked;
 
 	/* reset the trace */
-	__wakeup_reset(tr);
+	__wakeup_reset(wakeup_trace);
 
 	wakeup_cpu = task_cpu(p);
 	wakeup_prio = p->prio;
@@ -274,74 +261,37 @@ wakeup_check_start(struct trace_array *tr, struct task_struct *p,
 
 	local_save_flags(flags);
 
-	tr->data[wakeup_cpu]->preempt_timestamp = ftrace_now(cpu);
-	trace_function(tr, tr->data[wakeup_cpu],
-		       CALLER_ADDR1, CALLER_ADDR2, flags);
+	wakeup_trace->data[wakeup_cpu]->preempt_timestamp = ftrace_now(cpu);
+	trace_function(wakeup_trace, wakeup_trace->data[wakeup_cpu],
+		       CALLER_ADDR1, CALLER_ADDR2, flags, pc);
 
 out_locked:
 	__raw_spin_unlock(&wakeup_lock);
 out:
-	atomic_dec(&tr->data[cpu]->disabled);
-}
-
-static notrace void
-wake_up_callback(void *probe_data, void *call_data,
-		 const char *format, va_list *args)
-{
-	struct trace_array **ptr = probe_data;
-	struct trace_array *tr = *ptr;
-	struct task_struct *curr;
-	struct task_struct *task;
-	struct rq *__rq;
-
-	if (likely(!tracer_enabled))
-		return;
-
-	/* Skip pid %d state %ld */
-	(void)va_arg(*args, int);
-	(void)va_arg(*args, long);
-	/* now get the meat: "rq %p task %p rq->curr %p" */
-	__rq = va_arg(*args, typeof(__rq));
-	task = va_arg(*args, typeof(task));
-	curr = va_arg(*args, typeof(curr));
-
-	tracing_record_cmdline(task);
-	tracing_record_cmdline(curr);
-
-	wakeup_check_start(tr, task, curr);
+	atomic_dec(&wakeup_trace->data[cpu]->disabled);
 }
 
 static void start_wakeup_tracer(struct trace_array *tr)
 {
 	int ret;
 
-	ret = marker_probe_register("kernel_sched_wakeup",
-			"pid %d state %ld ## rq %p task %p rq->curr %p",
-			wake_up_callback,
-			&wakeup_trace);
+	ret = register_trace_sched_wakeup(probe_wakeup);
 	if (ret) {
-		pr_info("wakeup trace: Couldn't add marker"
+		pr_info("wakeup trace: Couldn't activate tracepoint"
 			" probe to kernel_sched_wakeup\n");
 		return;
 	}
 
-	ret = marker_probe_register("kernel_sched_wakeup_new",
-			"pid %d state %ld ## rq %p task %p rq->curr %p",
-			wake_up_callback,
-			&wakeup_trace);
+	ret = register_trace_sched_wakeup_new(probe_wakeup);
 	if (ret) {
-		pr_info("wakeup trace: Couldn't add marker"
+		pr_info("wakeup trace: Couldn't activate tracepoint"
 			" probe to kernel_sched_wakeup_new\n");
 		goto fail_deprobe;
 	}
 
-	ret = marker_probe_register("kernel_sched_schedule",
-		"prev_pid %d next_pid %d prev_state %ld "
-		"## rq %p prev %p next %p",
-		sched_switch_callback,
-		&wakeup_trace);
+	ret = register_trace_sched_switch(probe_wakeup_sched_switch);
 	if (ret) {
-		pr_info("sched trace: Couldn't add marker"
+		pr_info("sched trace: Couldn't activate tracepoint"
 			" probe to kernel_sched_schedule\n");
 		goto fail_deprobe_wake_new;
 	}
@@ -363,28 +313,18 @@ static void start_wakeup_tracer(struct trace_array *tr)
 
 	return;
 fail_deprobe_wake_new:
-	marker_probe_unregister("kernel_sched_wakeup_new",
-				wake_up_callback,
-				&wakeup_trace);
+	unregister_trace_sched_wakeup_new(probe_wakeup);
 fail_deprobe:
-	marker_probe_unregister("kernel_sched_wakeup",
-				wake_up_callback,
-				&wakeup_trace);
+	unregister_trace_sched_wakeup(probe_wakeup);
 }
 
 static void stop_wakeup_tracer(struct trace_array *tr)
 {
 	tracer_enabled = 0;
 	unregister_ftrace_function(&trace_ops);
-	marker_probe_unregister("kernel_sched_schedule",
-				sched_switch_callback,
-				&wakeup_trace);
-	marker_probe_unregister("kernel_sched_wakeup_new",
-				wake_up_callback,
-				&wakeup_trace);
-	marker_probe_unregister("kernel_sched_wakeup",
-				wake_up_callback,
-				&wakeup_trace);
+	unregister_trace_sched_switch(probe_wakeup_sched_switch);
+	unregister_trace_sched_wakeup_new(probe_wakeup);
+	unregister_trace_sched_wakeup(probe_wakeup);
 }
 
 static void wakeup_tracer_init(struct trace_array *tr)
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 0911b7e..09cf230 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -9,65 +9,29 @@ static inline int trace_valid_entry(struct trace_entry *entry)
 	case TRACE_FN:
 	case TRACE_CTX:
 	case TRACE_WAKE:
+	case TRACE_CONT:
 	case TRACE_STACK:
+	case TRACE_PRINT:
 	case TRACE_SPECIAL:
 		return 1;
 	}
 	return 0;
 }
 
-static int
-trace_test_buffer_cpu(struct trace_array *tr, struct trace_array_cpu *data)
+static int trace_test_buffer_cpu(struct trace_array *tr, int cpu)
 {
-	struct trace_entry *entries;
-	struct page *page;
-	int idx = 0;
-	int i;
+	struct ring_buffer_event *event;
+	struct trace_entry *entry;
 
-	BUG_ON(list_empty(&data->trace_pages));
-	page = list_entry(data->trace_pages.next, struct page, lru);
-	entries = page_address(page);
+	while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) {
+		entry = ring_buffer_event_data(event);
 
-	check_pages(data);
-	if (head_page(data) != entries)
-		goto failed;
-
-	/*
-	 * The starting trace buffer always has valid elements,
-	 * if any element exists.
-	 */
-	entries = head_page(data);
-
-	for (i = 0; i < tr->entries; i++) {
-
-		if (i < data->trace_idx && !trace_valid_entry(&entries[idx])) {
+		if (!trace_valid_entry(entry)) {
 			printk(KERN_CONT ".. invalid entry %d ",
-				entries[idx].type);
+				entry->type);
 			goto failed;
 		}
-
-		idx++;
-		if (idx >= ENTRIES_PER_PAGE) {
-			page = virt_to_page(entries);
-			if (page->lru.next == &data->trace_pages) {
-				if (i != tr->entries - 1) {
-					printk(KERN_CONT ".. entries buffer mismatch");
-					goto failed;
-				}
-			} else {
-				page = list_entry(page->lru.next, struct page, lru);
-				entries = page_address(page);
-			}
-			idx = 0;
-		}
 	}
-
-	page = virt_to_page(entries);
-	if (page->lru.next != &data->trace_pages) {
-		printk(KERN_CONT ".. too many entries");
-		goto failed;
-	}
-
 	return 0;
 
  failed:
@@ -89,13 +53,11 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
 	/* Don't allow flipping of max traces now */
 	raw_local_irq_save(flags);
 	__raw_spin_lock(&ftrace_max_lock);
-	for_each_possible_cpu(cpu) {
-		if (!head_page(tr->data[cpu]))
-			continue;
 
-		cnt += tr->data[cpu]->trace_idx;
+	cnt = ring_buffer_entries(tr->buffer);
 
-		ret = trace_test_buffer_cpu(tr, tr->data[cpu]);
+	for_each_possible_cpu(cpu) {
+		ret = trace_test_buffer_cpu(tr, cpu);
 		if (ret)
 			break;
 	}
@@ -120,11 +82,11 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 					   struct trace_array *tr,
 					   int (*func)(void))
 {
-	unsigned long count;
-	int ret;
 	int save_ftrace_enabled = ftrace_enabled;
 	int save_tracer_enabled = tracer_enabled;
+	unsigned long count;
 	char *func_name;
+	int ret;
 
 	/* The ftrace test PASSED */
 	printk(KERN_CONT "PASSED\n");
@@ -157,6 +119,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 	/* enable tracing */
 	tr->ctrl = 1;
 	trace->init(tr);
+
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
 
@@ -212,10 +175,10 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 int
 trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
 {
-	unsigned long count;
-	int ret;
 	int save_ftrace_enabled = ftrace_enabled;
 	int save_tracer_enabled = tracer_enabled;
+	unsigned long count;
+	int ret;
 
 	/* make sure msleep has been recorded */
 	msleep(1);
@@ -415,6 +378,15 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 }
 #endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */
 
+#ifdef CONFIG_NOP_TRACER
+int
+trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr)
+{
+	/* What could possibly go wrong? */
+	return 0;
+}
+#endif
+
 #ifdef CONFIG_SCHED_TRACER
 static int trace_wakeup_test_thread(void *data)
 {
@@ -486,6 +458,9 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
 
 	wake_up_process(p);
 
+	/* give a little time to let the thread wake up */
+	msleep(100);
+
 	/* stop the tracing. */
 	tr->ctrl = 0;
 	trace->ctrl_update(tr);
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
new file mode 100644
index 0000000..74c5d9a
--- /dev/null
+++ b/kernel/trace/trace_stack.c
@@ -0,0 +1,310 @@
+/*
+ * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
+ *
+ */
+#include <linux/stacktrace.h>
+#include <linux/kallsyms.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/debugfs.h>
+#include <linux/ftrace.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include "trace.h"
+
+#define STACK_TRACE_ENTRIES 500
+
+static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] =
+	 { [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX };
+static unsigned stack_dump_index[STACK_TRACE_ENTRIES];
+
+static struct stack_trace max_stack_trace = {
+	.max_entries		= STACK_TRACE_ENTRIES,
+	.entries		= stack_dump_trace,
+};
+
+static unsigned long max_stack_size;
+static raw_spinlock_t max_stack_lock =
+	(raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+
+static int stack_trace_disabled __read_mostly;
+static DEFINE_PER_CPU(int, trace_active);
+
+static inline void check_stack(void)
+{
+	unsigned long this_size, flags;
+	unsigned long *p, *top, *start;
+	int i;
+
+	this_size = ((unsigned long)&this_size) & (THREAD_SIZE-1);
+	this_size = THREAD_SIZE - this_size;
+
+	if (this_size <= max_stack_size)
+		return;
+
+	raw_local_irq_save(flags);
+	__raw_spin_lock(&max_stack_lock);
+
+	/* a race could have already updated it */
+	if (this_size <= max_stack_size)
+		goto out;
+
+	max_stack_size = this_size;
+
+	max_stack_trace.nr_entries	= 0;
+	max_stack_trace.skip		= 3;
+
+	save_stack_trace(&max_stack_trace);
+
+	/*
+	 * Now find where in the stack these are.
+	 */
+	i = 0;
+	start = &this_size;
+	top = (unsigned long *)
+		(((unsigned long)start & ~(THREAD_SIZE-1)) + THREAD_SIZE);
+
+	/*
+	 * Loop through all the entries. One of the entries may
+	 * for some reason be missed on the stack, so we may
+	 * have to account for them. If they are all there, this
+	 * loop will only happen once. This code only takes place
+	 * on a new max, so it is far from a fast path.
+	 */
+	while (i < max_stack_trace.nr_entries) {
+
+		stack_dump_index[i] = this_size;
+		p = start;
+
+		for (; p < top && i < max_stack_trace.nr_entries; p++) {
+			if (*p == stack_dump_trace[i]) {
+				this_size = stack_dump_index[i++] =
+					(top - p) * sizeof(unsigned long);
+				/* Start the search from here */
+				start = p + 1;
+			}
+		}
+
+		i++;
+	}
+
+ out:
+	__raw_spin_unlock(&max_stack_lock);
+	raw_local_irq_restore(flags);
+}
+
+static void
+stack_trace_call(unsigned long ip, unsigned long parent_ip)
+{
+	int cpu, resched;
+
+	if (unlikely(!ftrace_enabled || stack_trace_disabled))
+		return;
+
+	resched = need_resched();
+	preempt_disable_notrace();
+
+	cpu = raw_smp_processor_id();
+	/* no atomic needed, we only modify this variable by this cpu */
+	if (per_cpu(trace_active, cpu)++ != 0)
+		goto out;
+
+	check_stack();
+
+ out:
+	per_cpu(trace_active, cpu)--;
+	/* prevent recursion in schedule */
+	if (resched)
+		preempt_enable_no_resched_notrace();
+	else
+		preempt_enable_notrace();
+}
+
+static struct ftrace_ops trace_ops __read_mostly =
+{
+	.func = stack_trace_call,
+};
+
+static ssize_t
+stack_max_size_read(struct file *filp, char __user *ubuf,
+		    size_t count, loff_t *ppos)
+{
+	unsigned long *ptr = filp->private_data;
+	char buf[64];
+	int r;
+
+	r = snprintf(buf, sizeof(buf), "%ld\n", *ptr);
+	if (r > sizeof(buf))
+		r = sizeof(buf);
+	return simple_read_from_buffer(ubuf, count, ppos, buf, r);
+}
+
+static ssize_t
+stack_max_size_write(struct file *filp, const char __user *ubuf,
+		     size_t count, loff_t *ppos)
+{
+	long *ptr = filp->private_data;
+	unsigned long val, flags;
+	char buf[64];
+	int ret;
+
+	if (count >= sizeof(buf))
+		return -EINVAL;
+
+	if (copy_from_user(&buf, ubuf, count))
+		return -EFAULT;
+
+	buf[count] = 0;
+
+	ret = strict_strtoul(buf, 10, &val);
+	if (ret < 0)
+		return ret;
+
+	raw_local_irq_save(flags);
+	__raw_spin_lock(&max_stack_lock);
+	*ptr = val;
+	__raw_spin_unlock(&max_stack_lock);
+	raw_local_irq_restore(flags);
+
+	return count;
+}
+
+static struct file_operations stack_max_size_fops = {
+	.open		= tracing_open_generic,
+	.read		= stack_max_size_read,
+	.write		= stack_max_size_write,
+};
+
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	long i = (long)m->private;
+
+	(*pos)++;
+
+	i++;
+
+	if (i >= max_stack_trace.nr_entries ||
+	    stack_dump_trace[i] == ULONG_MAX)
+		return NULL;
+
+	m->private = (void *)i;
+
+	return &m->private;
+}
+
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
+	void *t = &m->private;
+	loff_t l = 0;
+
+	local_irq_disable();
+	__raw_spin_lock(&max_stack_lock);
+
+	for (; t && l < *pos; t = t_next(m, t, &l))
+		;
+
+	return t;
+}
+
+static void t_stop(struct seq_file *m, void *p)
+{
+	__raw_spin_unlock(&max_stack_lock);
+	local_irq_enable();
+}
+
+static int trace_lookup_stack(struct seq_file *m, long i)
+{
+	unsigned long addr = stack_dump_trace[i];
+#ifdef CONFIG_KALLSYMS
+	char str[KSYM_SYMBOL_LEN];
+
+	sprint_symbol(str, addr);
+
+	return seq_printf(m, "%s\n", str);
+#else
+	return seq_printf(m, "%p\n", (void*)addr);
+#endif
+}
+
+static int t_show(struct seq_file *m, void *v)
+{
+	long i = *(long *)v;
+	int size;
+
+	if (i < 0) {
+		seq_printf(m, "        Depth   Size      Location"
+			   "    (%d entries)\n"
+			   "        -----   ----      --------\n",
+			   max_stack_trace.nr_entries);
+		return 0;
+	}
+
+	if (i >= max_stack_trace.nr_entries ||
+	    stack_dump_trace[i] == ULONG_MAX)
+		return 0;
+
+	if (i+1 == max_stack_trace.nr_entries ||
+	    stack_dump_trace[i+1] == ULONG_MAX)
+		size = stack_dump_index[i];
+	else
+		size = stack_dump_index[i] - stack_dump_index[i+1];
+
+	seq_printf(m, "%3ld) %8d   %5d   ", i, stack_dump_index[i], size);
+
+	trace_lookup_stack(m, i);
+
+	return 0;
+}
+
+static struct seq_operations stack_trace_seq_ops = {
+	.start		= t_start,
+	.next		= t_next,
+	.stop		= t_stop,
+	.show		= t_show,
+};
+
+static int stack_trace_open(struct inode *inode, struct file *file)
+{
+	int ret;
+
+	ret = seq_open(file, &stack_trace_seq_ops);
+	if (!ret) {
+		struct seq_file *m = file->private_data;
+		m->private = (void *)-1;
+	}
+
+	return ret;
+}
+
+static struct file_operations stack_trace_fops = {
+	.open		= stack_trace_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+};
+
+static __init int stack_trace_init(void)
+{
+	struct dentry *d_tracer;
+	struct dentry *entry;
+
+	d_tracer = tracing_init_dentry();
+
+	entry = debugfs_create_file("stack_max_size", 0644, d_tracer,
+				    &max_stack_size, &stack_max_size_fops);
+	if (!entry)
+		pr_warning("Could not create debugfs 'stack_max_size' entry\n");
+
+	entry = debugfs_create_file("stack_trace", 0444, d_tracer,
+				    NULL, &stack_trace_fops);
+	if (!entry)
+		pr_warning("Could not create debugfs 'stack_trace' entry\n");
+
+	register_ftrace_function(&trace_ops);
+
+	return 0;
+}
+
+device_initcall(stack_trace_init);
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index db58fb6..9587d3b 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -241,7 +241,7 @@ static void stack_reset(struct trace_array *tr)
 	tr->time_start = ftrace_now(tr->cpu);
 
 	for_each_online_cpu(cpu)
-		tracing_reset(tr->data[cpu]);
+		tracing_reset(tr, cpu);
 }
 
 static void start_stack_trace(struct trace_array *tr)