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| author |   Ingo Molnar <mingo@elte.hu> | 2007-02-16 01:28:13 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-16 08:13:59 -0800 |
| commit | 82f67cd9fca8c8762c15ba7ed0d5747588c1e221 (patch) | |
| tree | 1ff7e5cc496580b85bb42fb1d7b19dcbef7b7776 /lib | |
| parent | [PATCH] hrtimers: prevent possible itimer DoS (diff) | |
| download | linux-dev-82f67cd9fca8c8762c15ba7ed0d5747588c1e221.tar.xz linux-dev-82f67cd9fca8c8762c15ba7ed0d5747588c1e221.zip | |
[PATCH] Add debugging feature /proc/timer_stat
Add /proc/timer_stats support: debugging feature to profile timer expiration.
Both the starting site, process/PID and the expiration function is captured.
This allows the quick identification of timer event sources in a system.
Sample output:
# echo 1 > /proc/timer_stats
# cat /proc/timer_stats
Timer Stats Version: v0.1
Sample period: 4.010 s
24, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick)
11, 0 swapper sk_reset_timer (tcp_delack_timer)
6, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick)
2, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
17, 0 swapper hrtimer_restart_sched_tick (hrtimer_sched_tick)
2, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
4, 2050 pcscd do_nanosleep (hrtimer_wakeup)
5, 4179 sshd sk_reset_timer (tcp_write_timer)
4, 2248 yum-updatesd schedule_timeout (process_timeout)
18, 0 swapper hrtimer_restart_sched_tick (hrtimer_sched_tick)
3, 0 swapper sk_reset_timer (tcp_delack_timer)
1, 1 swapper neigh_table_init_no_netlink (neigh_periodic_timer)
2, 1 swapper e1000_up (e1000_watchdog)
1, 1 init schedule_timeout (process_timeout)
100 total events, 25.24 events/sec
[ cleanups and hrtimers support from Thomas Gleixner <tglx@linutronix.de> ]
[bunk@stusta.de: nr_entries can become static]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 63f04c15e6f5..4448f91b865c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -134,6 +134,17 @@ config SCHEDSTATS application, you can say N to avoid the very slight overhead this adds. +config TIMER_STATS + bool "Collect kernel timers statistics" + depends on DEBUG_KERNEL && PROC_FS + help + If you say Y here, additional code will be inserted into the + timer routines to collect statistics about kernel timers being + reprogrammed. The statistics can be read from /proc/timer_stats. + The statistics collection is started by writing 1 to /proc/timer_stats, + writing 0 stops it. This feature is useful to collect information + about timer usage patterns in kernel and userspace. + config DEBUG_SLAB bool "Debug slab memory allocations" depends on DEBUG_KERNEL && SLAB |