From: Valentin Schneider <valentin.schneider@arm.com>
To: Vincent Guittot <vincent.guittot@linaro.org>,
mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
dietmar.eggemann@arm.com, rostedt@goodmis.org,
bsegall@google.com, mgorman@suse.de, bristot@redhat.com,
linux-kernel@vger.kernel.org, joel@joelfernandes.org
Cc: fweisbec@gmail.com, tglx@linutronix.de, qais.yousef@arm.com,
Vincent Guittot <vincent.guittot@linaro.org>
Subject: Re: [PATCH 0/7 v4] move update blocked load outside newidle_balance
Date: Wed, 24 Feb 2021 18:46:23 +0000 [thread overview]
Message-ID: <jhjblc95mo0.mognet@arm.com> (raw)
In-Reply-To: <20210224133007.28644-1-vincent.guittot@linaro.org>
On 24/02/21 14:30, Vincent Guittot wrote:
> Joel reported long preempt and irq off sequence in newidle_balance because
> of a large number of CPU cgroups in use and having to be updated. This
> patchset moves the update outside newidle_imblance. This enables to early
> abort during the updates in case of pending irq as an example.
>
> Instead of kicking a normal ILB that will wakes up CPU which is already
> idle, patch 6 triggers the update of statistics in the idle thread of
> the CPU before selecting and entering an idle state.
>
> Changes on v4:
> - Add a dedicated bit for updating blocked load when entering idle.
> This simplifies the management of concurrency with kick_ilb.
>
I believe that solves the issues vs nohz balance.
One last thing for patch 7: mayhaps we could do a tad better to avoid
duplicate updates going through a heapful of leaf cfs rqs, see
http://lore.kernel.org/r/jhj4kiht7oh.mognet@arm.com
Otherwise, feel free to add to the lot:
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
next prev parent reply other threads:[~2021-02-24 18:48 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-24 13:30 [PATCH 0/7 v4] move update blocked load outside newidle_balance Vincent Guittot
2021-02-24 13:30 ` [PATCH 1/7 v4] sched/fair: remove update of blocked load from newidle_balance Vincent Guittot
2021-03-02 9:01 ` [tip: sched/core] sched/fair: Remove " tip-bot2 for Vincent Guittot
2021-03-03 9:49 ` tip-bot2 for Vincent Guittot
2021-03-06 11:42 ` tip-bot2 for Vincent Guittot
2021-02-24 13:30 ` [PATCH 2/7 v4] sched/fair: remove unused return of _nohz_idle_balance Vincent Guittot
2021-03-02 9:01 ` [tip: sched/core] sched/fair: Remove " tip-bot2 for Vincent Guittot
2021-03-03 9:49 ` tip-bot2 for Vincent Guittot
2021-03-06 11:42 ` tip-bot2 for Vincent Guittot
2021-02-24 13:30 ` [PATCH 3/7 v4] sched/fair: remove unused parameter of update_nohz_stats Vincent Guittot
2021-03-02 9:01 ` [tip: sched/core] sched/fair: Remove " tip-bot2 for Vincent Guittot
2021-03-03 9:49 ` tip-bot2 for Vincent Guittot
2021-03-05 13:55 ` [PATCH 3/7 v4] sched/fair: remove " Qais Yousef
2021-03-06 11:42 ` [tip: sched/core] sched/fair: Remove " tip-bot2 for Vincent Guittot
2021-02-24 13:30 ` [PATCH 4/7 v4] sched/fair: merge for each idle cpu loop of ILB Vincent Guittot
2021-03-02 9:01 ` [tip: sched/core] sched/fair: Merge " tip-bot2 for Vincent Guittot
2021-03-03 9:49 ` tip-bot2 for Vincent Guittot
2021-03-06 11:42 ` tip-bot2 for Vincent Guittot
2021-02-24 13:30 ` [PATCH 5/7 v4] sched/fair: reorder newidle_balance pulled_task tests Vincent Guittot
2021-03-02 9:01 ` [tip: sched/core] sched/fair: Reorder " tip-bot2 for Vincent Guittot
2021-03-03 9:49 ` tip-bot2 for Vincent Guittot
2021-03-06 11:42 ` tip-bot2 for Vincent Guittot
2021-02-24 13:30 ` [PATCH 6/7 v4] sched/fair: trigger the update of blocked load on newly idle cpu Vincent Guittot
2021-03-02 9:01 ` [tip: sched/core] sched/fair: Trigger " tip-bot2 for Vincent Guittot
2021-03-03 9:49 ` tip-bot2 for Vincent Guittot
2021-03-05 13:52 ` [PATCH 6/7 v4] sched/fair: trigger " Qais Yousef
2021-03-06 11:42 ` [tip: sched/core] sched/fair: Trigger " tip-bot2 for Vincent Guittot
2021-02-24 13:30 ` [PATCH 7/7 v4] sched/fair: reduce the window for duplicated update Vincent Guittot
2021-03-02 9:01 ` [tip: sched/core] sched/fair: Reduce " tip-bot2 for Vincent Guittot
2021-03-03 9:49 ` tip-bot2 for Vincent Guittot
2021-03-06 11:42 ` tip-bot2 for Vincent Guittot
2021-02-24 15:53 ` [PATCH 0/7 v4] move update blocked load outside newidle_balance Peter Zijlstra
2021-02-24 15:57 ` Vincent Guittot
2021-02-24 17:41 ` Peter Zijlstra
2021-02-24 17:51 ` Vincent Guittot
2021-02-24 18:17 ` Peter Zijlstra
2021-02-24 18:46 ` Valentin Schneider [this message]
2021-02-25 8:05 ` Vincent Guittot
2021-02-25 12:14 ` Valentin Schneider
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