Messages in this thread Patch in this message | | | Date | Wed, 9 Jan 2013 17:38:07 +0000 | From | Morten Rasmussen <> | Subject | Re: [PATCH v3 04/22] sched: don't need go to smaller sched domain |
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On Sat, Jan 05, 2013 at 08:37:33AM +0000, Alex Shi wrote: > If parent sched domain has no task allowed cpu find. neither find in > it's child. So, go out to save useless checking. > > Signed-off-by: Alex Shi <alex.shi@intel.com> > --- > kernel/sched/fair.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 3c7b09a..ecfbf8e 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -3378,10 +3378,8 @@ select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags) > load_idx = sd->wake_idx; > > group = find_idlest_group(sd, p, cpu, load_idx);
The previous patch changed the behavior of find_idlest_group() to returning the local group if it is suitable. This effectively means that you remove the recursive search for a suitable idle sched group. You could as well merge find_idlest_group() and find_idlest_cpu() to avoid iterating through the cpus of the same sched group twice.
Morten
> - if (!group) { > - sd = sd->child; > - continue; > - } > + if (!group) > + goto unlock; > > new_cpu = find_idlest_cpu(group, p, cpu); > > -- > 1.7.12 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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