* [PATCH] sched: deduplicate mm checks in normalize_rt_tasks()
@ 2011-04-21 13:15 Hillf Danton
2011-04-21 13:29 ` Yong Zhang
0 siblings, 1 reply; 4+ messages in thread
From: Hillf Danton @ 2011-04-21 13:15 UTC (permalink / raw)
To: LKML; +Cc: Ingo Molnar, Peter Zijlstra
When normalizing realtime tasks, only user tasks are concerned by
checking their ->mm.
If the task is not realtime, the -mm is checked again, thus the
overwork could be removed.
Signed-off-by: Hillf Danton <dhillf@gmail.com>
---
--- a/kernel/sched.c 2011-03-30 03:09:48.000000000 +0800
+++ b/kernel/sched.c 2011-04-21 20:59:28.000000000 +0800
@@ -8364,7 +8364,7 @@ void normalize_rt_tasks(void)
* Renice negative nice level userspace
* tasks back to 0:
*/
- if (TASK_NICE(p) < 0 && p->mm)
+ if (TASK_NICE(p) < 0)
set_user_nice(p, 0);
continue;
}
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] sched: deduplicate mm checks in normalize_rt_tasks()
2011-04-21 13:15 [PATCH] sched: deduplicate mm checks in normalize_rt_tasks() Hillf Danton
@ 2011-04-21 13:29 ` Yong Zhang
2011-04-21 13:43 ` Yong Zhang
0 siblings, 1 reply; 4+ messages in thread
From: Yong Zhang @ 2011-04-21 13:29 UTC (permalink / raw)
To: Hillf Danton; +Cc: LKML, Ingo Molnar, Peter Zijlstra
On Thu, Apr 21, 2011 at 09:15:56PM +0800, Hillf Danton wrote:
> When normalizing realtime tasks, only user tasks are concerned by
> checking their ->mm.
> If the task is not realtime, the -mm is checked again, thus the
> overwork could be removed.
>
> Signed-off-by: Hillf Danton <dhillf@gmail.com>
> ---
>
> --- a/kernel/sched.c 2011-03-30 03:09:48.000000000 +0800
> +++ b/kernel/sched.c 2011-04-21 20:59:28.000000000 +0800
> @@ -8364,7 +8364,7 @@ void normalize_rt_tasks(void)
> * Renice negative nice level userspace
> * tasks back to 0:
> */
> - if (TASK_NICE(p) < 0 && p->mm)
> + if (TASK_NICE(p) < 0)
This looks good.
And we can also move TASK_NICE(p) < 0 to the upper if(),
like:
if (!rt_task(p) && TASK_NICE(p) < 0) {
set_user_nice(p, 0);
continue;
}
to reduce one level if() to make code cleaner :)
Thanks,
Yong
> set_user_nice(p, 0);
> continue;
> }
> --
> 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/
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] sched: deduplicate mm checks in normalize_rt_tasks()
2011-04-21 13:29 ` Yong Zhang
@ 2011-04-21 13:43 ` Yong Zhang
2011-04-21 13:50 ` Hillf Danton
0 siblings, 1 reply; 4+ messages in thread
From: Yong Zhang @ 2011-04-21 13:43 UTC (permalink / raw)
To: Hillf Danton; +Cc: LKML, Ingo Molnar, Peter Zijlstra
On Thu, Apr 21, 2011 at 09:29:04PM +0800, Yong Zhang wrote:
> On Thu, Apr 21, 2011 at 09:15:56PM +0800, Hillf Danton wrote:
> > When normalizing realtime tasks, only user tasks are concerned by
> > checking their ->mm.
> > If the task is not realtime, the -mm is checked again, thus the
> > overwork could be removed.
> >
> > Signed-off-by: Hillf Danton <dhillf@gmail.com>
> > ---
> >
> > --- a/kernel/sched.c 2011-03-30 03:09:48.000000000 +0800
> > +++ b/kernel/sched.c 2011-04-21 20:59:28.000000000 +0800
> > @@ -8364,7 +8364,7 @@ void normalize_rt_tasks(void)
> > * Renice negative nice level userspace
> > * tasks back to 0:
> > */
> > - if (TASK_NICE(p) < 0 && p->mm)
> > + if (TASK_NICE(p) < 0)
>
> This looks good.
>
> And we can also move TASK_NICE(p) < 0 to the upper if(),
> like:
> if (!rt_task(p) && TASK_NICE(p) < 0) {
> set_user_nice(p, 0);
> continue;
> }
>
> to reduce one level if() to make code cleaner :)
Damm, I'm wrong here, just ignore it.
Yours is good.
Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
>
> Thanks,
> Yong
>
> > set_user_nice(p, 0);
> > continue;
> > }
> > --
> > 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/
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] sched: deduplicate mm checks in normalize_rt_tasks()
2011-04-21 13:43 ` Yong Zhang
@ 2011-04-21 13:50 ` Hillf Danton
0 siblings, 0 replies; 4+ messages in thread
From: Hillf Danton @ 2011-04-21 13:50 UTC (permalink / raw)
To: Yong Zhang; +Cc: LKML, Ingo Molnar, Peter Zijlstra
On Thu, Apr 21, 2011 at 9:43 PM, Yong Zhang <yong.zhang0@gmail.com> wrote:
> On Thu, Apr 21, 2011 at 09:29:04PM +0800, Yong Zhang wrote:
>> On Thu, Apr 21, 2011 at 09:15:56PM +0800, Hillf Danton wrote:
>> > When normalizing realtime tasks, only user tasks are concerned by
>> > checking their ->mm.
>> > If the task is not realtime, the -mm is checked again, thus the
>> > overwork could be removed.
>> >
>> > Signed-off-by: Hillf Danton <dhillf@gmail.com>
>> > ---
>> >
>> > --- a/kernel/sched.c 2011-03-30 03:09:48.000000000 +0800
>> > +++ b/kernel/sched.c 2011-04-21 20:59:28.000000000 +0800
>> > @@ -8364,7 +8364,7 @@ void normalize_rt_tasks(void)
>> > * Renice negative nice level userspace
>> > * tasks back to 0:
>> > */
>> > - if (TASK_NICE(p) < 0 && p->mm)
>> > + if (TASK_NICE(p) < 0)
>>
>> This looks good.
>>
>> And we can also move TASK_NICE(p) < 0 to the upper if(),
>> like:
>> if (!rt_task(p) && TASK_NICE(p) < 0) {
>> set_user_nice(p, 0);
>> continue;
>> }
>>
>> to reduce one level if() to make code cleaner :)
>
> Damm, I'm wrong here, just ignore it.
>
Hi Yong
We could not be fine every time, right?
thanks
Hillf
> Yours is good.
>
> Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
>
>>
>> Thanks,
>> Yong
>>
>> > set_user_nice(p, 0);
>> > continue;
>> > }
>> > --
>> > 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/
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2011-04-21 13:50 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2011-04-21 13:15 [PATCH] sched: deduplicate mm checks in normalize_rt_tasks() Hillf Danton
2011-04-21 13:29 ` Yong Zhang
2011-04-21 13:43 ` Yong Zhang
2011-04-21 13:50 ` Hillf Danton
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