[026/151] hrtimer: Fix /proc/timer_list regression

Greg KH
2009-12-17T04:45:14Z

From: Feng Tang <feng.tang@intel.com>

commit 8629ea2eaba8ca0de2e38ce1b4a825e16255976e upstream.

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@intel.com>
LKML-Reference: <alpine.LFD.2.00.0911181933540.24119@localhost.localdomain>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
include/linux/hrtimer.h | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -446,7 +446,7 @@ extern void timer_stats_update_stats(voi

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_st

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));
}