[PATCH] sleep profiling

Implement prof=sleep profiling.  TASK_UNINTERRUPTIBLE sleeps will be taken
as a profile hit, and every millisecond spent sleeping causes a profile-hit
for the call site that initiated the sleep.

Sample readprofile output on i386:

   306 ps2_sendbyte                               1.3973
   432 call_usermodehelper_keys                   1.9548
   484 ps2_command                                0.6453
   790 __driver_attach                            4.7879
  1593 msleep                                    44.2500
  3976 sync_buffer                               64.1290
  4076 do_lookup                                 12.4648
  8587 sync_page                                122.6714
 20820 total                                      0.0067

(NOTE: architectures need to check whether get_wchan() can be called from
deep within the wakeup path.)

akpm: we need to mark more functions __sched.  lock_sock(), msleep(), others..

akpm: the contention in do_lookup() is a surprise.  Presumably doing disk
reads for directory contents while holding i_mutex.

[akpm@osdl.org: various fixes]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Ingo Molnar 2006-12-06 20:37:24 -08:00 committed by Linus Torvalds
parent 70888bd5b7
commit ece8a684c7
4 changed files with 65 additions and 10 deletions

View file

@ -6,10 +6,15 @@
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/cpumask.h>
#include <linux/cache.h>
#include <asm/errno.h>
extern int prof_on __read_mostly;
#define CPU_PROFILING 1
#define SCHED_PROFILING 2
#define SLEEP_PROFILING 3
struct proc_dir_entry;
struct pt_regs;
@ -18,7 +23,24 @@ struct notifier_block;
/* init basic kernel profiler */
void __init profile_init(void);
void profile_tick(int);
void profile_hit(int, void *);
/*
* Add multiple profiler hits to a given address:
*/
void profile_hits(int, void *ip, unsigned int nr_hits);
/*
* Single profiler hit:
*/
static inline void profile_hit(int type, void *ip)
{
/*
* Speedup for the common (no profiling enabled) case:
*/
if (unlikely(prof_on == type))
profile_hits(type, ip, 1);
}
#ifdef CONFIG_PROC_FS
void create_prof_cpu_mask(struct proc_dir_entry *);
#else