[tip:timers/urgent] hrtimer: Fix /proc/timer_list regression

From: tip-bot for Feng Tang
Date: Fri Nov 20 2009 - 05:31:52 EST


Commit-ID: 8629ea2eaba8ca0de2e38ce1b4a825e16255976e
Gitweb: http://git.kernel.org/tip/8629ea2eaba8ca0de2e38ce1b4a825e16255976e
Author: Feng Tang <feng.tang@xxxxxxxxx>
AuthorDate: Thu, 3 Sep 2009 16:32:53 +0800
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 20 Nov 2009 11:25:48 +0100

hrtimer: Fix /proc/timer_list regression

commit 507e1231 (timer stats: Optimize by adding quick check to avoid
function calls) introduced a regression in /proc/timer_list.

/proc/timer_list shows now
#0: <c27d46b0>, tick_sched_timer, S:01, <(null)>, /-1
instead of
#0: <c27d46b0>, tick_sched_timer, S:01, hrtimer_start, swapper/0

Revert the hrtimer quick check for now. The optimization needs more
thought, but this is neither 2.6.32-rc7 nor stable material.

[ tglx: - Removed unrelated changes from the original patch
- Prevent unneccesary call to timer_stats_update_stats
- massaged the changelog ]

Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx>
LKML-Reference: <alpine.LFD.2.00.0911181933540.24119@xxxxxxxxxxxxxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: stable@xxxxxxxxxx
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
include/linux/hrtimer.h | 4 +---
1 files changed, 1 insertions(+), 3 deletions(-)

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index ff037f0..9bace4b 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -446,7 +446,7 @@ extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,

static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
{
- if (likely(!timer->start_site))
+ if (likely(!timer_stats_active))
return;
timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
timer->function, timer->start_comm, 0);
@@ -457,8 +457,6 @@ extern void __timer_stats_hrtimer_set_start_info(struct hrtimer *timer,

static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
{
- if (likely(!timer_stats_active))
- return;
__timer_stats_hrtimer_set_start_info(timer, __builtin_return_address(0));
}

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