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-rw-r--r--init/Kconfig34
-rw-r--r--init/main.c41
2 files changed, 61 insertions, 14 deletions
diff --git a/init/Kconfig b/init/Kconfig
index d4e9671..9b68fee 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -933,6 +933,40 @@ config AIO
by some high performance threaded applications. Disabling
this option saves about 7k.
+config HAVE_PERF_COUNTERS
+ bool
+
+menu "Performance Counters"
+
+config PERF_COUNTERS
+ bool "Kernel Performance Counters"
+ depends on HAVE_PERF_COUNTERS
+ select ANON_INODES
+ help
+ Enable kernel support for performance counter hardware.
+
+ Performance counters are special hardware registers available
+ on most modern CPUs. These registers count the number of certain
+ types of hw events: such as instructions executed, cachemisses
+ suffered, or branches mis-predicted - without slowing down the
+ kernel or applications. These registers can also trigger interrupts
+ when a threshold number of events have passed - and can thus be
+ used to profile the code that runs on that CPU.
+
+ The Linux Performance Counter subsystem provides an abstraction of
+ these hardware capabilities, available via a system call. It
+ provides per task and per CPU counters, and it provides event
+ capabilities on top of those.
+
+ Say Y if unsure.
+
+config EVENT_PROFILE
+ bool "Tracepoint profile sources"
+ depends on PERF_COUNTERS && EVENT_TRACER
+ default y
+
+endmenu
+
config VM_EVENT_COUNTERS
default y
bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
diff --git a/init/main.c b/init/main.c
index 9d759d6..5616661 100644
--- a/init/main.c
+++ b/init/main.c
@@ -534,6 +534,16 @@ void __init __weak thread_info_cache_init(void)
{
}
+/*
+ * Set up kernel memory allocators
+ */
+static void __init mm_init(void)
+{
+ mem_init();
+ kmem_cache_init();
+ vmalloc_init();
+}
+
asmlinkage void __init start_kernel(void)
{
char * command_line;
@@ -575,6 +585,23 @@ asmlinkage void __init start_kernel(void)
setup_nr_cpu_ids();
smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
+ build_all_zonelists();
+ page_alloc_init();
+
+ printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
+ parse_early_param();
+ parse_args("Booting kernel", static_command_line, __start___param,
+ __stop___param - __start___param,
+ &unknown_bootoption);
+ /*
+ * These use large bootmem allocations and must precede
+ * kmem_cache_init()
+ */
+ pidhash_init();
+ vfs_caches_init_early();
+ sort_main_extable();
+ trap_init();
+ mm_init();
/*
* Set up the scheduler prior starting any interrupts (such as the
* timer interrupt). Full topology setup happens at smp_init()
@@ -586,26 +613,16 @@ asmlinkage void __init start_kernel(void)
* fragile until we cpu_idle() for the first time.
*/
preempt_disable();
- build_all_zonelists();
- page_alloc_init();
- printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
- parse_early_param();
- parse_args("Booting kernel", static_command_line, __start___param,
- __stop___param - __start___param,
- &unknown_bootoption);
if (!irqs_disabled()) {
printk(KERN_WARNING "start_kernel(): bug: interrupts were "
"enabled *very* early, fixing it\n");
local_irq_disable();
}
- sort_main_extable();
- trap_init();
rcu_init();
/* init some links before init_ISA_irqs() */
early_irq_init();
init_IRQ();
prio_tree_init();
- pidhash_init();
init_timers();
hrtimers_init();
softirq_init();
@@ -647,14 +664,10 @@ asmlinkage void __init start_kernel(void)
initrd_start = 0;
}
#endif
- vmalloc_init();
- vfs_caches_init_early();
cpuset_init_early();
page_cgroup_init();
- mem_init();
enable_debug_pagealloc();
cpu_hotplug_init();
- kmem_cache_init();
kmemtrace_init();
kmemleak_init();
debug_objects_mem_init();
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