Messages in this thread | | | Date | Wed, 26 Aug 2015 23:57:59 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH 1/3] timer: Optimize fastpath_timer_check() |
| |
On Tue, Aug 25, 2015 at 08:17:46PM -0700, Jason Low wrote: > In fastpath_timer_check(), the task_cputime() function is always > called to compute the utime and stime values. However, this is not > necessary if there are no per-thread timers to check for. This patch > modifies the code such that we compute the task_cputime values only > when there are per-thread timers set. > > Signed-off-by: Jason Low <jason.low2@hp.com>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Thanks.
> --- > kernel/time/posix-cpu-timers.c | 15 +++++++-------- > 1 files changed, 7 insertions(+), 8 deletions(-) > > diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c > index 892e3da..02596ff 100644 > --- a/kernel/time/posix-cpu-timers.c > +++ b/kernel/time/posix-cpu-timers.c > @@ -1117,16 +1117,15 @@ static inline int task_cputime_expired(const struct task_cputime *sample, > static inline int fastpath_timer_check(struct task_struct *tsk) > { > struct signal_struct *sig; > - cputime_t utime, stime; > - > - task_cputime(tsk, &utime, &stime); > > if (!task_cputime_zero(&tsk->cputime_expires)) { > - struct task_cputime task_sample = { > - .utime = utime, > - .stime = stime, > - .sum_exec_runtime = tsk->se.sum_exec_runtime > - }; > + struct task_cputime task_sample; > + cputime_t utime, stime; > + > + task_cputime(tsk, &utime, &stime); > + task_sample.utime = utime; > + task_sample.stime = stime; > + task_sample.sum_exec_runtime = tsk->se.sum_exec_runtime; > > if (task_cputime_expired(&task_sample, &tsk->cputime_expires)) > return 1; > -- > 1.7.2.5 >
| |