Messages in this thread | | | Subject | Re: [PATCH] sched: remove redundant check in select_task_rq_fair | From | Peter Zijlstra <> | Date | Tue, 07 Jun 2011 11:53:34 +0200 |
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On Tue, 2011-06-07 at 15:18 +0530, Nikunj A. Dadhania wrote: > When balancing for wakeup affinity, a redundant check can removed.
Yes, tempting, but no, now you've got an extra call to wake_affine(), which is more expensive.
> Signed-off-by: Nikunj A. Dadhania <nikunj@linux.vnet.ibm.com> > --- > kernel/sched_fair.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c > index 433491c..b9e5701 100644 > --- a/kernel/sched_fair.c > +++ b/kernel/sched_fair.c > @@ -1753,7 +1753,7 @@ select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags) > } > > if (affine_sd) { > - if (cpu == prev_cpu || wake_affine(affine_sd, p, sync)) > + if (wake_affine(affine_sd, p, sync)) > prev_cpu = cpu; > > new_cpu = select_idle_sibling(p, prev_cpu); >
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