From: Tim Chen <tim.c.chen@linux.intel.com>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: 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
Subject: Re: [PATCH v3 0/5] Improve newidle lb cost tracking and early abort
Date: Thu, 28 Oct 2021 14:36:08 -0700 [thread overview]
Message-ID: <8f6b4ab17a319117cbed8751aa4fa9f2d6e0ca5b.camel@linux.intel.com> (raw)
In-Reply-To: <20211028121530.GA19512@vingu-book>
On Thu, 2021-10-28 at 14:15 +0200, Vincent Guittot wrote:
>
> > It seems to make sense to skip the call
> > to nohz_newidle_balance() for this case?
>
> nohz_newidle_balance() also tests this condition :
> (this_rq->avg_idle < sysctl_sched_migration_cost)
> and doesn't set NOHZ_NEWILB_KICKi in such case
>
> But this patch now used the condition :
> this_rq->avg_idle < sd->max_newidle_lb_cost
> and sd->max_newidle_lb_cost can be higher than
> sysctl_sched_migration_cost
>
> which means that we can set NOHZ_NEWILB_KICK:
> -although we decided to skip newidle loop
> -or when we abort because this_rq->avg_idle < curr_cost + sd-
> >max_newidle_lb_cost
>
> This is even more true when sysctl_sched_migration_cost is lowered
> which is your case IIRC
>
> The patch below ensures that we don't set NOHZ_NEWILB_KICK in such
> cases:
>
Thanks. Will ask our benchmark team to give it a spin.
Tim
next prev parent reply other threads:[~2021-10-28 21:36 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-19 12:35 Vincent Guittot
2021-10-19 12:35 ` [PATCH v3 1/5] sched/fair: Account update_blocked_averages in newidle_balance cost Vincent Guittot
2021-10-21 9:43 ` Mel Gorman
2021-10-31 10:16 ` [tip: sched/core] " tip-bot2 for Vincent Guittot
2021-10-19 12:35 ` [PATCH v3 2/5] sched/fair: Skip update_blocked_averages if we are defering load balance Vincent Guittot
2021-10-21 9:44 ` Mel Gorman
2021-10-21 12:45 ` Vincent Guittot
2021-10-31 10:16 ` [tip: sched/core] " tip-bot2 for Vincent Guittot
2021-10-19 12:35 ` [PATCH 3/5] sched/fair: Wait before decaying max_newidle_lb_cost Vincent Guittot
2021-10-21 9:45 ` Mel Gorman
2021-10-29 10:01 ` Dietmar Eggemann
2021-10-29 12:19 ` Vincent Guittot
2021-10-31 10:16 ` [tip: sched/core] " tip-bot2 for Vincent Guittot
2021-10-19 12:35 ` [PATCH v3 4/5] sched/fair: Remove sysctl_sched_migration_cost condition Vincent Guittot
2021-10-21 9:46 ` Mel Gorman
2021-10-29 10:01 ` Dietmar Eggemann
2021-10-29 12:30 ` Vincent Guittot
2021-10-31 10:16 ` [tip: sched/core] " tip-bot2 for Vincent Guittot
2021-10-19 12:35 ` [PATCH v3 5/5] sched/fair: cleanup newidle_balance Vincent Guittot
2021-10-21 9:46 ` Mel Gorman
2021-10-31 10:16 ` [tip: sched/core] sched/fair: Cleanup newidle_balance tip-bot2 for Vincent Guittot
2021-10-21 9:52 ` [PATCH v3 0/5] Improve newidle lb cost tracking and early abort Mel Gorman
2021-10-21 12:42 ` Vincent Guittot
2021-10-26 17:25 ` Tim Chen
2021-10-27 8:49 ` Vincent Guittot
2021-10-27 20:53 ` Tim Chen
2021-10-28 12:15 ` Vincent Guittot
2021-10-28 21:36 ` Tim Chen [this message]
2021-10-29 17:00 ` Tim Chen
2021-10-31 10:18 ` Vincent Guittot
2021-10-28 23:25 ` Joel Fernandes
2021-10-29 7:49 ` Vincent Guittot
2021-10-29 19:37 ` Joel Fernandes
2021-10-29 10:01 ` Dietmar Eggemann
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