From: Subhra Mazumdar <subhra.mazumdar@oracle.com>
To: Patrick Bellasi <patrick.bellasi@arm.com>
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
mingo@redhat.com, tglx@linutronix.de, steven.sistare@oracle.com,
dhaval.giani@oracle.com, daniel.lezcano@linaro.org,
vincent.guittot@linaro.org, viresh.kumar@linaro.org,
tim.c.chen@linux.intel.com, mgorman@techsingularity.net,
parth@linux.ibm.com
Subject: Re: [RFC PATCH 3/9] sched: add sched feature to disable idle core search
Date: Thu, 5 Sep 2019 15:02:09 -0700 [thread overview]
Message-ID: <031de1c0-c5a5-ea88-1e9c-836452fccf9c@oracle.com> (raw)
In-Reply-To: <87mufj2gju.fsf@arm.com>
On 9/5/19 3:17 AM, Patrick Bellasi wrote:
> On Fri, Aug 30, 2019 at 18:49:38 +0100, subhra mazumdar wrote...
>
>> Add a new sched feature SIS_CORE to have an option to disable idle core
>> search (select_idle_core).
>>
>> Signed-off-by: subhra mazumdar <subhra.mazumdar@oracle.com>
>> ---
>> kernel/sched/features.h | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/kernel/sched/features.h b/kernel/sched/features.h
>> index 858589b..de4d506 100644
>> --- a/kernel/sched/features.h
>> +++ b/kernel/sched/features.h
>> @@ -57,6 +57,7 @@ SCHED_FEAT(TTWU_QUEUE, true)
>> */
>> SCHED_FEAT(SIS_AVG_CPU, false)
>> SCHED_FEAT(SIS_PROP, true)
>> +SCHED_FEAT(SIS_CORE, true)
> Why do we need a sched_feature? If you think there are systems in
> which the usage of latency-nice does not make sense for in "Select Idle
> Sibling", then we should probably better add a new Kconfig option.
This is not for latency-nice but to be able to disable a different aspect
of the scheduler, i.e searching for idle cores. This can be made part of
latency-nice (i.e not do idle core search if latency-nice is below a
certain value) but even then having a feature to disable it doesn't hurt.
>
> If that's the case, you can probably use the init/Kconfig's
> "Scheduler features" section, recently added by:
>
> commit 69842cba9ace ("sched/uclamp: Add CPU's clamp buckets refcounting")
>
>> /*
>> * Issue a WARN when we do multiple update_rq_clock() calls
> Best,
> Patrick
>
next prev parent reply other threads:[~2019-09-05 22:06 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-30 17:49 [RFC PATCH 0/9] Task latency-nice subhra mazumdar
2019-08-30 17:49 ` [RFC PATCH 1/9] sched,cgroup: Add interface for latency-nice subhra mazumdar
2019-09-04 17:32 ` Tim Chen
2019-09-05 6:15 ` Parth Shah
2019-09-05 10:11 ` Patrick Bellasi
2019-09-06 12:22 ` Parth Shah
2019-09-05 8:31 ` Peter Zijlstra
2019-09-05 9:45 ` Patrick Bellasi
2019-09-05 10:46 ` Peter Zijlstra
2019-09-05 11:13 ` Qais Yousef
2019-09-05 11:30 ` Peter Zijlstra
2019-09-05 11:40 ` Patrick Bellasi
2019-09-05 11:48 ` Peter Zijlstra
2019-09-05 13:32 ` Qais Yousef
2019-09-05 11:47 ` Qais Yousef
2020-04-16 0:02 ` Joel Fernandes
2020-04-16 17:23 ` Dietmar Eggemann
2020-04-18 16:01 ` Joel Fernandes
2020-04-20 11:26 ` Parth Shah
2020-04-20 19:14 ` Joel Fernandes
2020-04-20 11:47 ` Qais Yousef
2020-04-20 19:10 ` Joel Fernandes
2019-09-05 11:30 ` Patrick Bellasi
2019-09-05 11:47 ` Peter Zijlstra
2019-09-05 11:18 ` Patrick Bellasi
2019-09-05 11:40 ` Peter Zijlstra
2019-09-05 11:46 ` Patrick Bellasi
2019-09-05 11:46 ` Valentin Schneider
2019-09-05 13:07 ` Patrick Bellasi
2019-09-05 14:48 ` Valentin Schneider
2019-09-06 12:45 ` Parth Shah
2019-09-06 14:13 ` Valentin Schneider
2019-09-06 14:32 ` Vincent Guittot
2019-09-06 17:10 ` Parth Shah
2019-09-06 22:50 ` Valentin Schneider
2019-09-06 12:31 ` Parth Shah
2019-09-05 10:05 ` Patrick Bellasi
2019-09-05 10:48 ` Peter Zijlstra
2019-08-30 17:49 ` [RFC PATCH 2/9] sched: add search limit as per latency-nice subhra mazumdar
2019-09-05 6:22 ` Parth Shah
2019-08-30 17:49 ` [RFC PATCH 3/9] sched: add sched feature to disable idle core search subhra mazumdar
2019-09-05 10:17 ` Patrick Bellasi
2019-09-05 22:02 ` Subhra Mazumdar [this message]
2019-08-30 17:49 ` [RFC PATCH 4/9] sched: SIS_CORE " subhra mazumdar
2019-09-05 10:19 ` Patrick Bellasi
2019-08-30 17:49 ` [RFC PATCH 5/9] sched: Define macro for number of CPUs in core subhra mazumdar
2019-08-30 17:49 ` [RFC PATCH 6/9] x86/smpboot: Optimize cpumask_weight_sibling macro for x86 subhra mazumdar
2019-08-30 17:49 ` [RFC PATCH 7/9] sched: search SMT before LLC domain subhra mazumdar
2019-09-05 9:31 ` Peter Zijlstra
2019-09-05 20:40 ` Subhra Mazumdar
2019-08-30 17:49 ` [RFC PATCH 8/9] sched: introduce per-cpu var next_cpu to track search limit subhra mazumdar
2019-08-30 17:49 ` [RFC PATCH 9/9] sched: rotate the cpu search window for better spread subhra mazumdar
2019-09-05 6:37 ` Parth Shah
2019-09-05 5:55 ` [RFC PATCH 0/9] Task latency-nice Parth Shah
2019-09-05 10:31 ` Patrick Bellasi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=031de1c0-c5a5-ea88-1e9c-836452fccf9c@oracle.com \
--to=subhra.mazumdar@oracle.com \
--cc=daniel.lezcano@linaro.org \
--cc=dhaval.giani@oracle.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mgorman@techsingularity.net \
--cc=mingo@redhat.com \
--cc=parth@linux.ibm.com \
--cc=patrick.bellasi@arm.com \
--cc=peterz@infradead.org \
--cc=steven.sistare@oracle.com \
--cc=tglx@linutronix.de \
--cc=tim.c.chen@linux.intel.com \
--cc=vincent.guittot@linaro.org \
--cc=viresh.kumar@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.