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* Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds2010-03-131-6/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: tracing: Do not record user stack trace from NMI context tracing: Disable buffer switching when starting or stopping trace tracing: Use same local variable when resetting the ring buffer function-graph: Init curr_ret_stack with ret_stack ring-buffer: Move disabled check into preempt disable section function-graph: Add tracing_thresh support to function_graph tracer tracing: Update the comm field in the right variable in update_max_tr function-graph: Use comment notation for func names of dangling '}' function-graph: Fix unused reference to ftrace_set_func() tracing: Fix warning in s_next of trace file ops tracing: Include irqflags headers from trace clock
| * ring-buffer: Move disabled check into preempt disable sectionLai Jiangshan2010-03-121-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ring buffer resizing and resetting relies on a schedule RCU action. The buffers are disabled, a synchronize_sched() is called and then the resize or reset takes place. But this only works if the disabling of the buffers are within the preempt disabled section, otherwise a window exists that the buffers can be written to while a reset or resize takes place. Cc: stable@kernel.org Reported-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4B949E43.2010906@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge branch 'for-next' into for-linusJiri Kosina2010-03-081-2/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: Documentation/filesystems/proc.txt arch/arm/mach-u300/include/mach/debug-macro.S drivers/net/qlge/qlge_ethtool.c drivers/net/qlge/qlge_main.c drivers/net/typhoon.c
| * | Fix misspellings of "truly" in comments.Adam Buchbinder2010-02-041-2/+2
| |/ | | | | | | | | | | | | Some comments misspell "truly"; this fixes them. No code changes. Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | Merge branch 'master' into percpuTejun Heo2010-02-021-5/+23
|\ \ | |/
| * ring-buffer: Check for end of page in iteratorSteven Rostedt2010-01-261-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | If the iterator comes to an empty page for some reason, or if the page is emptied by a consuming read. The iterator code currently does not check if the iterator is pass the contents, and may return a false entry. This patch adds a check to the ring buffer iterator to test if the current page has been completely read and sets the iterator to the next page if necessary. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Check if ring buffer iterator has stale dataSteven Rostedt2010-01-261-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Usually reads of the ring buffer is performed by a single task. There are two types of reads from the ring buffer. One is a consuming read which will consume the entry that was read and the next read will be the entry that follows. The other is an iterator that will let the user read the contents of the ring buffer without modifying it. When an iterator is allocated, writes to the ring buffer are disabled to protect the iterator. The problem exists when consuming reads happen while an iterator is allocated. Specifically, the kind of read that swaps out an entire page (used by splice) and replaces it with a new read. If the iterator is on the page that is swapped out, then the next read may read from this swapped out page and return garbage. This patch adds a check when reading the iterator to make sure that the iterator contents are still valid. If a consuming read has taken place, the iterator is reset. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Add rb_list_head() wrapper around new reader page next fieldSteven Rostedt2010-01-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | If the very unlikely case happens where the writer moves the head by one between where the head page is read and where the new reader page is assigned _and_ the writer then writes and wraps the entire ring buffer so that the head page is back to what was originally read as the head page, the page to be swapped will have a corrupted next pointer. Simple solution is to wrap the assignment of the next pointer with a rb_list_head(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Wrap a list.next reference with rb_list_head()David Sharp2010-01-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reference at the end of rb_get_reader_page() was causing off-by-one writes to the prev pointer of the page after the reader page when that page is the head page, and therefore the reader page has the RB_PAGE_HEAD flag in its list.next pointer. This eventually results in a GPF in a subsequent call to rb_set_head_page() (usually from rb_get_reader_page()) when that prev pointer is dereferenced. The dereferenced register would characteristically have an address that appears shifted left by one byte (eg, ffxxxxxxxxxxxxyy instead of ffffxxxxxxxxxxxx) due to being written at an address one byte too high. Signed-off-by: David Sharp <dhsharp@google.com> LKML-Reference: <1262826727-9090-1-git-send-email-dhsharp@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | local_t: Move local.h include to ringbuffer.c and ring_buffer_benchmark.cChristoph Lameter2010-01-051-0/+1
|/ | | | | | | | | ringbuffer*.c are the last users of local.h. Remove the include from modules.h and add it to ringbuffer files. Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds2009-12-161-18/+11
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: tracing: Fix return of trace_dump_stack() ksym_tracer: Fix bad cast tracing/power: Remove two exports tracing: Change event->profile_count to be int type tracing: Simplify trace_option_write() tracing: Remove useless trace option tracing: Use seq file for trace_clock tracing: Use seq file for trace_options function-graph: Allow writing the same val to set_graph_function ftrace: Call trace_parser_clear() properly ftrace: Return EINVAL when writing invalid val to set_ftrace_filter tracing: Move a printk out of ftrace_raw_reg_event_foo() tracing: Pull up calls to trace_define_common_fields() tracing: Extract duplicate ftrace_raw_init_event_foo() ftrace.h: Use common pr_info fmt string tracing: Add stack trace to irqsoff tracer tracing: Add trace_dump_stack() ring-buffer: Move resize integrity check under reader lock ring-buffer: Use sync sched protection on ring buffer resizing tracing: Fix wrong usage of strstrip in trace_ksyms
| * ring-buffer: Move resize integrity check under reader lockSteven Rostedt2009-12-101-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While using an application that does splice on the ftrace ring buffer at start up, I triggered an integrity check failure. Looking into this, I discovered that resizing the buffer performs an integrity check after the buffer is resized. This check unfortunately is preformed after it releases the reader lock. If a reader is reading the buffer it may cause the integrity check to trigger a false failure. This patch simply moves the integrity checker under the protection of the ring buffer reader lock. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Use sync sched protection on ring buffer resizingSteven Rostedt2009-12-101-16/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | There was a comment in the ring buffer code that says the calling layers should prevent tracing or reading of the ring buffer while resizing. I have discovered that the tracers do not honor this arrangement. This patch moves the disabling and synchronizing the ring buffer to a higher layer during resizing. This guarantees that no writes are occurring while the resize takes place. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | locking: Convert __raw_spin* functions to arch_spin*Thomas Gleixner2009-12-141-6/+6
| | | | | | | | | | | | | | | | | | | | Name space cleanup. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* | locking: Rename __RAW_SPIN_LOCK_UNLOCKED to __ARCH_SPIN_LOCK_UNLOCKEDThomas Gleixner2009-12-141-1/+1
| | | | | | | | | | | | | | | | | | | | Further name space cleanup. No functional change Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* | locking: Convert raw_spinlock to arch_spinlockThomas Gleixner2009-12-141-2/+2
|/ | | | | | | | | | | | | | | | | | | The raw_spin* namespace was taken by lockdep for the architecture specific implementations. raw_spin_* would be the ideal name space for the spinlocks which are not converted to sleeping locks in preempt-rt. Linus suggested to convert the raw_ to arch_ locks and cleanup the name space instead of using an artifical name like core_spin, atomic_spin or whatever No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
* Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2009-12-051-6/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (470 commits) x86: Fix comments of register/stack access functions perf tools: Replace %m with %a in sscanf hw-breakpoints: Keep track of user disabled breakpoints tracing/syscalls: Make syscall events print callbacks static tracing: Add DEFINE_EVENT(), DEFINE_SINGLE_EVENT() support to docbook perf: Don't free perf_mmap_data until work has been done perf_event: Fix compile error perf tools: Fix _GNU_SOURCE macro related strndup() build error trace_syscalls: Remove unused syscall_name_to_nr() trace_syscalls: Simplify syscall profile trace_syscalls: Remove duplicate init_enter_##sname() trace_syscalls: Add syscall_nr field to struct syscall_metadata trace_syscalls: Remove enter_id exit_id trace_syscalls: Set event_enter_##sname->data to its metadata trace_syscalls: Remove unused event_syscall_enter and event_syscall_exit perf_event: Initialize data.period in perf_swevent_hrtimer() perf probe: Simplify event naming perf probe: Add --list option for listing current probe events perf probe: Add argv_split() from lib/argv_split.c perf probe: Move probe event utility functions to probe-event.c ...
| * Merge commit 'v2.6.32-rc7' into perf/coreIngo Molnar2009-11-151-0/+2
| |\ | | | | | | | | | | | | | | | Merge reason: pick up perf fixlets Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * \ Merge commit 'v2.6.32-rc6' into perf/coreIngo Molnar2009-11-041-6/+6
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: tools/perf/Makefile Merge reason: Resolve the conflict, merge to upstream and merge in perf fixes so we can add a dependent patch. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | tracing/events: Add 'signed' field to format filesTom Zanussi2009-10-061-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sign info used for filters in the kernel is also useful to applications that process the trace stream. Add it to the format files and make it available to userspace. Signed-off-by: Tom Zanussi <tzanussi@gmail.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: rostedt@goodmis.org Cc: lizf@cn.fujitsu.com Cc: hch@infradead.org Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <1254809398-8078-2-git-send-email-tzanussi@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | Merge branch 'tracing-core-for-linus' of ↵Linus Torvalds2009-12-051-6/+3
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (40 commits) tracing: Separate raw syscall from syscall tracer ring-buffer-benchmark: Add parameters to set produce/consumer priorities tracing, function tracer: Clean up strstrip() usage ring-buffer benchmark: Run producer/consumer threads at nice +19 tracing: Remove the stale include/trace/power.h tracing: Only print objcopy version warning once from recordmcount tracing: Prevent build warning: 'ftrace_graph_buf' defined but not used ring-buffer: Move access to commit_page up into function used tracing: do not disable interrupts for trace_clock_local ring-buffer: Add multiple iterations between benchmark timestamps kprobes: Sanitize struct kretprobe_instance allocations tracing: Fix to use __always_unused attribute compiler: Introduce __always_unused tracing: Exit with error if a weak function is used in recordmcount.pl tracing: Move conditional into update_funcs() in recordmcount.pl tracing: Add regex for weak functions in recordmcount.pl tracing: Move mcount section search to front of loop in recordmcount.pl tracing: Fix objcopy revision check in recordmcount.pl tracing: Check absolute path of input file in recordmcount.pl tracing: Correct the check for number of arguments in recordmcount.pl ...
| * | | ring-buffer: Move access to commit_page up into function usedSteven Rostedt2009-11-171-6/+3
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | With the change of the way we process commits. Where a commit only happens at the outer most level, and that we don't need to worry about a commit ending after the rb_start_commit() has been called, the code use to grab the commit page before the tail page to prevent a possible race. But this race no longer exists with the rb_start_commit() rb_end_commit() interface. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ring-buffer: Synchronize resizing buffer with reader lockLai Jiangshan2009-11-041-0/+2
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We got a sudden panic when we reduced the size of the ringbuffer. We can reproduce the panic by the following steps: echo 1 > events/sched/enable cat trace_pipe > /dev/null & while ((1)) do echo 12000 > buffer_size_kb echo 512 > buffer_size_kb done (not more than 5 seconds, panic ...) Reported-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4AF01735.9060409@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | tracing: Remove cpu arg from the rb_time_stamp() functionJiri Olsa2009-10-241-5/+5
| | | | | | | | | | | | | | | | | | | | | | The cpu argument is not used inside the rb_time_stamp() function. Plus fix a typo. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091023233647.118547500@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | tracing: Fix comment typo and documentation exampleJiri Olsa2009-10-241-1/+1
|/ | | | | | | | | | | Trivial patch to fix a documentation example and to fix a comment. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091023233646.871719877@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* includecheck fix: kernel/trace, ring_buffer.cJaswinder Singh Rajput2009-09-201-2/+0
| | | | | | | | | | | | fix the following 'make includecheck' warning: kernel/trace/ring_buffer.c: trace.h is included more than once. Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Sam Ravnborg <sam@ravnborg.org> LKML-Reference: <1247068617.4382.107.camel@ht.satnam>
* ring-buffer: typecast cmpxchg to fix PowerPC warningSteven Rostedt2009-09-141-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The cmpxchg used by PowerPC does the following: ({ \ __typeof__(*(ptr)) _o_ = (o); \ __typeof__(*(ptr)) _n_ = (n); \ (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ (unsigned long)_n_, sizeof(*(ptr))); \ }) This does a type check of *ptr to both o and n. Unfortunately, the code in ring-buffer.c assigns longs to pointers and pointers to longs and causes a warning on PowerPC: ring_buffer.c: In function 'rb_head_page_set': ring_buffer.c:704: warning: initialization makes pointer from integer without a cast ring_buffer.c:704: warning: initialization makes pointer from integer without a cast ring_buffer.c: In function 'rb_head_page_replace': ring_buffer.c:797: warning: initialization makes integer from pointer without a cast This patch adds the typecasts inside cmpxchg to annotate that a long is being cast to a pointer and a pointer is being casted to a long and this removes the PowerPC warnings. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: consolidate interface of rb_buffer_peek()Robert Richter2009-09-091-7/+4
| | | | | | | | | | | rb_buffer_peek() operates with struct ring_buffer_per_cpu *cpu_buffer only. Thus, instead of passing variables buffer and cpu it is better to use cpu_buffer directly. This also reduces the risk of races since cpu_buffer is not calculated twice. Signed-off-by: Robert Richter <robert.richter@amd.com> LKML-Reference: <1249045084-3028-1-git-send-email-robert.richter@amd.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: only enable ring_buffer_swap_cpu when neededSteven Rostedt2009-09-041-0/+4
| | | | | | | | | | | Since the ability to swap the cpu buffers adds a small overhead to the recording of a trace, we only want to add it when needed. Only the irqsoff and preemptoff tracers use this feature, and both are not recommended for production kernels. This patch disables its use when neither irqsoff nor preemptoff is configured. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: check for swapped buffers in start of committingSteven Rostedt2009-09-041-3/+17
| | | | | | | | | | Because the irqsoff tracer can swap an internal CPU buffer, it is possible that a swap happens between the start of the write and before the committing bit is set (the committing bit will disable swapping). This patch adds a check for this and will fail the write if it detects it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: disable all cpu buffers when one finds a problemSteven Rostedt2009-09-041-8/+13
| | | | | | | | | | | | | | | Currently the way RB_WARN_ON works, is to disable either the current CPU buffer or all CPU buffers, depending on whether a ring_buffer or ring_buffer_per_cpu struct was passed into the macro. Most users of the RB_WARN_ON pass in the CPU buffer, so only the one CPU buffer gets disabled but the rest are still active. This may confuse users even though a warning is sent to the console. This patch changes the macro to disable the entire buffer even if the CPU buffer is passed in. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: do not count discarded eventsSteven Rostedt2009-09-041-17/+54
| | | | | | | | | | | | | | | | The latency tracers report the number of items in the trace buffer. This uses the ring buffer data to calculate this. Because discarded events are also counted, the numbers do not match the number of items that are printed. The ring buffer also adds a "padding" item to the end of each buffer page which also gets counted as a discarded item. This patch decrements the counter to the page entries on a discard. This allows us to ignore discarded entries while reading the buffer. Decrementing the counter is still safe since it can only happen while the committing flag is still set. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: remove ring_buffer_event_discardSteven Rostedt2009-09-041-21/+6
| | | | | | | | | | | | | | | | | The function ring_buffer_event_discard can be used on any item in the ring buffer, even after the item was committed. This function provides no safety nets and is very race prone. An item may be safely removed from the ring buffer before it is committed with the ring_buffer_discard_commit. Since there are currently no users of this function, and because this function is racey and error prone, this patch removes it altogether. Note, removing this function also allows the counters to ignore all discarded events (patches will follow). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: fix ring_buffer_read crossing pagesSteven Rostedt2009-09-041-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | When the ring buffer uses an iterator (static read mode, not on the fly reading), when it crosses a page boundery, it will skip the first entry on the next page. The reason is that the last entry of a page is usually padding if the page is not full. The padding will not be returned to the user. The problem arises on ring_buffer_read because it also increments the iterator. Because both the read and peek use the same rb_iter_peek, the rb_iter_peak will return the padding but also increment to the next item. This is because the ring_buffer_peek will not incerment it itself. The ring_buffer_read will increment it again and then call rb_iter_peek again to get the next item. But that will be the second item, not the first one on the page. The reason this never showed up before, is because the ftrace utility always calls ring_buffer_peek first and only uses ring_buffer_read to increment to the next item. The ring_buffer_peek will always keep the pointer to a valid item and not padding. This just hid the bug. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: remove unnecessary cpu_relaxSteven Rostedt2009-09-041-12/+4
| | | | | | | | | The loops in the ring buffer that use cpu_relax are not dependent on other CPUs. They simply came across some padding in the ring buffer and are skipping over them. It is a normal loop and does not require a cpu_relax. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: do not swap buffers during a commitSteven Rostedt2009-09-041-2/+9
| | | | | | | If a commit is taking place on a CPU ring buffer, do not allow it to be swapped. Return -EBUSY when this is detected instead. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ring-buffer: do not reset while in a commitSteven Rostedt2009-09-041-0/+4
| | | | | | | The callers of reset must ensure that no commit can be taking place at the time of the reset. If it does then we may corrupt the ring buffer. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge branch 'linus' into tracing/coreIngo Molnar2009-08-111-8/+7
|\ | | | | | | | | | | | | | | | | Conflicts: kernel/trace/trace_events_filter.c We use the tracing/core version. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * ring-buffer: Fix memleak in ring_buffer_free()Eric Dumazet2009-08-071-0/+1
| | | | | | | | | | | | | | | | | | | | I noticed oprofile memleaked in linux-2.6 current tree, and tracked this ring-buffer leak. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> LKML-Reference: <4A7C06B9.2090302@gmail.com> Cc: stable@kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: Fix advance of reader in rb_buffer_peek()Robert Richter2009-08-061-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When calling rb_buffer_peek() from ring_buffer_consume() and a padding event is returned, the function rb_advance_reader() is called twice. This may lead to missing samples or under high workloads to the warning below. This patch fixes this. If a padding event is returned by rb_buffer_peek() it will be consumed by the calling function now. Also, I simplified some code in ring_buffer_consume(). ------------[ cut here ]------------ WARNING: at /dev/shm/.source/linux/kernel/trace/ring_buffer.c:2289 rb_advance_reader+0x2e/0xc5() Hardware name: Anaheim Modules linked in: Pid: 29, comm: events/2 Tainted: G W 2.6.31-rc3-oprofile-x86_64-standard-00059-g5050dc2 #1 Call Trace: [<ffffffff8106776f>] ? rb_advance_reader+0x2e/0xc5 [<ffffffff81039ffe>] warn_slowpath_common+0x77/0x8f [<ffffffff8103a025>] warn_slowpath_null+0xf/0x11 [<ffffffff8106776f>] rb_advance_reader+0x2e/0xc5 [<ffffffff81068bda>] ring_buffer_consume+0xa0/0xd2 [<ffffffff81326933>] op_cpu_buffer_read_entry+0x21/0x9e [<ffffffff810be3af>] ? __find_get_block+0x4b/0x165 [<ffffffff8132749b>] sync_buffer+0xa5/0x401 [<ffffffff810be3af>] ? __find_get_block+0x4b/0x165 [<ffffffff81326c1b>] ? wq_sync_buffer+0x0/0x78 [<ffffffff81326c76>] wq_sync_buffer+0x5b/0x78 [<ffffffff8104aa30>] worker_thread+0x113/0x1ac [<ffffffff8104dd95>] ? autoremove_wake_function+0x0/0x38 [<ffffffff8104a91d>] ? worker_thread+0x0/0x1ac [<ffffffff8104dc9a>] kthread+0x88/0x92 [<ffffffff8100bdba>] child_rip+0xa/0x20 [<ffffffff8104dc12>] ? kthread+0x0/0x92 [<ffffffff8100bdb0>] ? child_rip+0x0/0x20 ---[ end trace f561c0a58fcc89bd ]--- Cc: Steven Rostedt <rostedt@goodmis.org> Cc: <stable@kernel.org> Signed-off-by: Robert Richter <robert.richter@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * ring-buffer: do not disable ring buffer on oops_in_progressSteven Rostedt2009-08-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit: commit e0fdace10e75dac67d906213b780ff1b1a4cc360 Author: David Miller <davem@davemloft.net> Date: Fri Aug 1 01:11:22 2008 -0700 debug_locks: set oops_in_progress if we will log messages. Otherwise lock debugging messages on runqueue locks can deadlock the system due to the wakeups performed by printk(). Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ingo Molnar <mingo@elte.hu> Will permanently set oops_in_progress on any lockdep failure. When this triggers it will cause any read from the ring buffer to permanently disable the ring buffer (not to mention no locking of printk). This patch removes the check. It keeps the print in NMI which makes sense. This is probably OK, since the ring buffer should not cause something to set oops_in_progress anyway. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: fix check of try_to_discard resultSteven Rostedt2009-08-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | The function ring_buffer_discard_commit inversed the code path of the result of try_to_discard. It should skip incrementing the entry counter if try_to_discard succeeded. But instead, it increments the entry conder if it succeeded to discard, and does not increment it if it fails. The result of this bug is that filtering will make the stat counters incorrect. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ring_buffer: Fix warning while ignoring cmpxchg return valueLai Jiangshan2009-07-161-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernel/trace/ring_buffer.c: In function 'rb_tail_page_update': kernel/trace/ring_buffer.c:849: warning: value computed is not used kernel/trace/ring_buffer.c:850: warning: value computed is not used Add "(void)"s to fix this warning, because we don't need here to handle the fail case of cmpxchg, it's fine if an interrupt already did the job. Changed from V1: Add a comment(which is written by Steven) for it. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* | ring-buffer: make locklessSteven Rostedt2009-07-071-148/+738
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch converts the ring buffers into a completely lockless buffer recording system. The read side still takes locks since we still serialize readers. But the writers are the ones that must be lockless (those can happen in NMIs). The main change is to the "head_page" pointer. We write to the tail, and read from the head. The "head_page" pointer in the cpu buffer is now just a reference to where to look. The real head page is now kept in the head_page->list->prev->next pointer. That is, in the list head of the previous page we set flags. The list pages are allocated to be aligned such that the lowest significant bits are always zero pointing to the list. This gives us play to put in flags to their pointers. bit 0: set when the page is a head page bit 1: set when the writer is moving the page (for overwrite mode) cmpxchg is used to update the pointer. When the writer wraps the buffer and the tail meets the head, in overwrite mode, the writer must move the head page forward. It first uses cmpxchg to change the pointer flag from 1 to 2. Once this is done, the reader on another CPU will not take the page from the buffer. The writers need to protect against interrupts (we don't bother with disabling interrupts because NMIs are allowed to write too). After the writer sets the pointer flag to 2, it takes care to manage interrupts coming in. This is discribed in detail within the comments of the code. Changes in version 2: - Let reader reset entries value of header page. - Fix tail page passing commit page on reader page test. - Always increment entries and write counter in rb_tail_page_update - Add safety check in rb_set_commit_to_write to break out of infinite loop - add mask in rb_is_reader_page [ Impact: lock free writing to the ring buffer ] Signed-off-by: Steven Rostedt <srostedt@redhat.com>
* | ring-buffer: make the buffer a true circular link listSteven Rostedt2009-07-071-17/+32
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch changes the ring buffer data pages from using a link list head pointer, to making each buffer page point to another buffer page and never back to a "head". This makes the handling of the ring buffer less complex, since the traversing of the ring buffer pages no longer needs to account for the head pointer. This change also is needed to make the ring buffer lockless. [ Changes in version 2: - Added change that Lai Jiangshan mentioned. From: Lai Jiangshan <laijs@cn.fujitsu.com> Date: Thu, 11 Jun 2009 11:25:48 +0800 LKML-Reference: <4A30793C.6090208@cn.fujitsu.com> I'm not sure whether these 4 lines: bpage = list_entry(pages.next, struct buffer_page, list); list_del_init(&bpage->list); cpu_buffer->pages = &bpage->list; list_splice(&pages, cpu_buffer->pages); equal to these 2 lines: cpu_buffer->pages = pages.next; list_del(&pages); If there are equivalent, I think the second one are simpler. It may be not a really necessarily cleanup. What I asked is: if there are equivalent, could you use these two line: cpu_buffer->pages = pages.next; list_del(&pages); ] [ Impact: simplify the ring buffer to help make it lockless ] Signed-off-by: Steven Rostedt <srostedt@redhat.com>
* ring-buffer: Make it generally availablePaul Mundt2009-06-251-0/+11
| | | | | | | | | | | | | | | | | In hunting down the cause for the hwlat_detector ring buffer spew in my failed -next builds it became obvious that folks are now treating ring_buffer as something that is generic independent of tracing and thus, suitable for public driver consumption. Given that there are only a few minor areas in ring_buffer that have any reliance on CONFIG_TRACING or CONFIG_FUNCTION_TRACER, provide stubs for those and make it generally available. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Cc: Jon Masters <jcm@jonmasters.org> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20090625053012.GB19944@linux-sh.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds2009-06-201-118/+193
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits) tracing/urgent: warn in case of ftrace_start_up inbalance tracing/urgent: fix unbalanced ftrace_start_up function-graph: add stack frame test function-graph: disable when both x86_32 and optimize for size are configured ring-buffer: have benchmark test print to trace buffer ring-buffer: do not grab locks in nmi ring-buffer: add locks around rb_per_cpu_empty ring-buffer: check for less than two in size allocation ring-buffer: remove useless compile check for buffer_page size ring-buffer: remove useless warn on check ring-buffer: use BUF_PAGE_HDR_SIZE in calculating index tracing: update sample event documentation tracing/filters: fix race between filter setting and module unload tracing/filters: free filter_string in destroy_preds() ring-buffer: use commit counters for commit pointer accounting ring-buffer: remove unused variable ring-buffer: have benchmark test handle discarded events ring-buffer: prevent adding write in discarded area tracing/filters: strloc should be unsigned short tracing/filters: operand can be negative ... Fix up kmemcheck-induced conflict in kernel/trace/ring_buffer.c manually
| * ring-buffer: do not grab locks in nmiSteven Rostedt2009-06-171-8/+51
| | | | | | | | | | | | | | | | | | | | | | | | If ftrace_dump_on_oops is set, and an NMI detects a lockup, then it will need to read from the ring buffer. But the read side of the ring buffer still takes locks. This patch adds a check on the read side that if it is in an NMI, then it will disable the ring buffer and not take any locks. Reads can still happen on a disabled ring buffer. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: add locks around rb_per_cpu_emptySteven Rostedt2009-06-171-2/+9
| | | | | | | | | | | | | | The checking of whether the buffer is empty or not needs to be serialized among the readers. Add the reader spin lock around it. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ring-buffer: check for less than two in size allocationSteven Rostedt2009-06-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | The ring buffer must have at least two pages allocated for the reader page swap to work. The page count check will miss the case of a zero size passed in. Even though a zero size ring buffer would probably fail an allocation, making the min size check for less than two instead of equal to one makes the code a bit more robust. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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