From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Aubrey Li <aubrey.li@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
Mel Gorman <mgorman@techsingularity.net>,
Rik van Riel <riel@surriel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Valentin Schneider <valentin.schneider@arm.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Gautham R Shenoy <ego@linux.vnet.ibm.com>,
Parth Shah <parth@linux.ibm.com>
Subject: Re: [PATCH v2 6/8] sched/idle: Move busy_cpu accounting to idle callback
Date: Mon, 17 May 2021 16:10:58 +0530 [thread overview]
Message-ID: <20210517104058.GW2633526@linux.vnet.ibm.com> (raw)
In-Reply-To: <5823f298-6fae-5a73-3ab8-f708d90a7e52@linux.intel.com>
* Aubrey Li <aubrey.li@linux.intel.com> [2021-05-14 12:11:50]:
> On 5/13/21 3:31 PM, Srikar Dronamraju wrote:
> > * Aubrey Li <aubrey.li@linux.intel.com> [2021-05-12 16:08:24]:
> >> On 5/7/21 12:45 AM, Srikar Dronamraju wrote:
<snip>
> >> Also, for those frequent context-switching tasks with very short idle,
> >> it's expensive for scheduler to mark idle/busy every time, that's why
> >> my patch only marks idle every time and marks busy ratelimited in
> >> scheduler tick.
> >>
> >
> > I have tried few tasks with very short idle times and updating nr_busy
> > everytime, doesnt seem to be impacting. Infact, it seems to help in picking
> > the idler-llc more often.
> >
>
> How many CPUs in your LLC?
I have tried with X86, 48 CPUs, 2 nodes, each having 24 CPUs in LLC
+
POWER10, Multiple CPUs with 4 CPUs in LLC
+
POWER9, Multiple CPUs with 8 CPUs in LLC
>
> This is a system with 192 CPUs, 4 nodes and each node has 48 CPUs in LLC
> domain.
>
Okay,
> It looks like for netperf both TCP and UDP cases have the notable change
> under 2 x overcommit, it may be not interesting though.
>
>
I believe the extra load on this 24 core LLC could be because we may end up
trying to set the idle-core, even when there is no idle core available.
If possible, can you please give a try with v3 with the call to
set_next_idle_core commented out?
--
Thanks and Regards
Srikar Dronamraju
next prev parent reply other threads:[~2021-05-17 10:41 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-06 16:45 [PATCH v2 0/8] sched/fair: wake_affine improvements Srikar Dronamraju
2021-05-06 16:45 ` [PATCH v2 1/8] sched/fair: Update affine statistics when needed Srikar Dronamraju
2021-05-07 16:08 ` Valentin Schneider
2021-05-07 17:05 ` Srikar Dronamraju
2021-05-11 11:51 ` Valentin Schneider
2021-05-11 16:22 ` Srikar Dronamraju
2021-05-06 16:45 ` [PATCH v2 2/8] sched/fair: Maintain the identity of idle-core Srikar Dronamraju
2021-05-11 11:51 ` Valentin Schneider
2021-05-11 16:27 ` Srikar Dronamraju
2021-05-06 16:45 ` [PATCH v2 3/8] sched/fair: Update idle-core more often Srikar Dronamraju
2021-05-06 16:45 ` [PATCH v2 4/8] sched/fair: Prefer idle CPU to cache affinity Srikar Dronamraju
2021-05-06 16:45 ` [PATCH v2 5/8] sched/fair: Use affine_idler_llc for wakeups across LLC Srikar Dronamraju
2021-05-06 16:45 ` [PATCH v2 6/8] sched/idle: Move busy_cpu accounting to idle callback Srikar Dronamraju
2021-05-11 11:51 ` Valentin Schneider
2021-05-11 16:55 ` Srikar Dronamraju
2021-05-12 0:32 ` Aubrey Li
2021-05-12 8:08 ` Aubrey Li
2021-05-13 7:31 ` Srikar Dronamraju
2021-05-14 4:11 ` Aubrey Li
2021-05-17 10:40 ` Srikar Dronamraju [this message]
2021-05-17 12:48 ` Aubrey Li
2021-05-17 12:57 ` Srikar Dronamraju
2021-05-18 0:59 ` Aubrey Li
2021-05-18 4:00 ` Srikar Dronamraju
2021-05-18 6:05 ` Aubrey Li
2021-05-18 7:18 ` Srikar Dronamraju
2021-05-19 9:43 ` Aubrey Li
2021-05-19 17:34 ` Srikar Dronamraju
2021-05-06 16:45 ` [PATCH v2 7/8] sched/fair: Remove ifdefs in waker_affine_idler_llc Srikar Dronamraju
2021-05-06 16:45 ` [PATCH v2 8/8] sched/fair: Dont iterate if no idle CPUs Srikar Dronamraju
2021-05-06 16:53 ` [PATCH v2 0/8] sched/fair: wake_affine improvements Srikar Dronamraju
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