diff options
| author | Steven Rostedt <[email protected]> | 2008-07-09 00:15:32 -0400 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2008-07-11 15:53:27 +0200 |
| commit | a83bc47c33ab182f1e48977fd5a04024d713c75e (patch) | |
| tree | 759eb1afc83271ee2815dbd1214635ec7b506b5c | |
| parent | c0c87734f125d2fa8ebc70310f3257fa6209f2b6 (diff) | |
sched_clock: record TSC after gtod
To read the gtod we need to grab the xtime lock for read. Reading the gtod
before the TSC can cause a bigger gab if the xtime lock is contended.
This patch simply reverses the order to read the TSC after the gtod.
The locking in the reading of the gtod handles any barriers one might
think is needed.
Signed-off-by: Steven Rostedt <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: john stultz <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | kernel/sched_clock.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched_clock.c b/kernel/sched_clock.c index ee7cce5029ce..28ff6bf5e02b 100644 --- a/kernel/sched_clock.c +++ b/kernel/sched_clock.c @@ -237,8 +237,8 @@ void sched_clock_tick(void) WARN_ON_ONCE(!irqs_disabled()); - now = sched_clock(); now_gtod = ktime_to_ns(ktime_get()); + now = sched_clock(); __raw_spin_lock(&scd->lock); __update_sched_clock(scd, now, NULL); |