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From: Valentin Schneider <valentin.schneider@arm.com>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Juri Lelli <juri.lelli@redhat.com>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
	Daniel Bristot de Oliveira <bristot@redhat.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Joel Fernandes <joel@joelfernandes.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Qais Yousef <qais.yousef@arm.com>
Subject: Re: [PATCH 0/7 v4] move update blocked load outside newidle_balance
Date: Thu, 25 Feb 2021 12:14:37 +0000	[thread overview]
Message-ID: <jhj1rd45ope.mognet@arm.com> (raw)
In-Reply-To: <CAKfTPtDjVBP676kzW-5QF8nMyD1+WNnJWH4=gKPVV+55tm3Cng@mail.gmail.com>

On 25/02/21 09:05, Vincent Guittot wrote:
>> 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
>
> rq->last_blocked_load_update_tick is there only to filter duplicate
> update during _nohz_idle_balance but not for other normal LB.
>

Right, update_nohz_stats() is now only used in _nohz_idle_balance()...
IIUC the pattern being covered here would be a CPUX getting kicked for nohz
stats/balance, then some CPUX-N (so it gets picked by find_new_ilb())
entering idle and getting kick in turn (less than a jiffy apart). 


      reply	other threads:[~2021-02-25 12:15 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
2021-02-25  8:05   ` Vincent Guittot
2021-02-25 12:14     ` Valentin Schneider [this message]

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