From: Steven Rostedt <rostedt@goodmis.org>
To: Qais Yousef <qais.yousef@arm.com>
Cc: Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Pavan Kondeti <pkondeti@codeaurora.org>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 6/6] sched/rt: Fix pushing unfit tasks to a better CPU
Date: Wed, 11 Mar 2020 10:00:20 -0400 [thread overview]
Message-ID: <20200311100020.63bb81e5@gandalf.local.home> (raw)
In-Reply-To: <20200302132721.8353-7-qais.yousef@arm.com>
On Mon, 2 Mar 2020 13:27:21 +0000
Qais Yousef <qais.yousef@arm.com> wrote:
> + * Don't bother moving it if the destination CPU is
> + * not running a lower priority task.
> + */
> + if (p->prio < cpu_rq(target)->rt.highest_prio.curr) {
> +
> + cpu = target;
> +
> + } else if (p->prio == cpu_rq(target)->rt.highest_prio.curr) {
> +
> + /*
> + * If the priority is the same and the new CPU
> + * is a better fit, then move, otherwise don't
> + * bother here either.
> + */
> + if (fit_target)
> + cpu = target;
> + }
BTW, A little better algorithm would be to test fit_target first:
target_prio = cpu_rq(target)->rt.hightest_prio.curr;
if (p->prio < target_prio) {
cpu = target;
} else if (fit_target && p->prio == target_prio) {
cpu = target;
}
Which can also just be a single if statement:
if (p->prio < target_prio ||
(fit_target && p->prio == target_prio)
cpu = target;
-- Steve
next prev parent reply other threads:[~2020-03-11 14:00 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-02 13:27 [PATCH v3 0/6] RT Capacity Awareness Fixes & Improvements Qais Yousef
2020-03-02 13:27 ` [PATCH v3 1/6] sched/rt: cpupri_find: Implement fallback mechanism for !fit case Qais Yousef
[not found] ` <20200304143200.GA13200@geo.homenetwork>
2020-03-04 15:18 ` Qais Yousef
2020-03-04 16:27 ` Steven Rostedt
2020-03-04 17:39 ` Qais Yousef
2020-03-04 18:54 ` Steven Rostedt
2020-03-04 20:01 ` Qais Yousef
2020-03-05 12:43 ` Qais Yousef
2020-03-10 14:22 ` Qais Yousef
2020-03-11 13:51 ` Steven Rostedt
2020-03-20 12:58 ` [tip: sched/core] sched/rt: cpupri_find: Trigger a full search as fallback tip-bot2 for Qais Yousef
2020-03-06 14:42 ` [tip: sched/core] sched/rt: cpupri_find: Implement fallback mechanism for !fit case tip-bot2 for Qais Yousef
2020-03-02 13:27 ` [PATCH v3 2/6] sched/rt: Re-instate old behavior in select_task_rq_rt Qais Yousef
2020-03-06 14:42 ` [tip: sched/core] sched/rt: Re-instate old behavior in select_task_rq_rt() tip-bot2 for Qais Yousef
2020-03-02 13:27 ` [PATCH v3 3/6] sched/rt: Optimize cpupri_find on non-heterogenous systems Qais Yousef
2020-03-06 14:42 ` [tip: sched/core] sched/rt: Optimize cpupri_find() " tip-bot2 for Qais Yousef
2020-03-02 13:27 ` [PATCH v3 4/6] sched/rt: Allow pulling unfitting task Qais Yousef
[not found] ` <20200304145219.GA14173@geo.homenetwork>
2020-03-04 15:28 ` Qais Yousef
2020-03-06 14:42 ` [tip: sched/core] " tip-bot2 for Qais Yousef
2020-03-02 13:27 ` [PATCH v3 5/6] sched/rt: Remove unnecessary push for unfit tasks Qais Yousef
2020-03-06 14:42 ` [tip: sched/core] " tip-bot2 for Qais Yousef
2020-03-02 13:27 ` [PATCH v3 6/6] sched/rt: Fix pushing unfit tasks to a better CPU Qais Yousef
2020-03-06 17:51 ` Qais Yousef
2020-03-11 10:53 ` Pavan Kondeti
2020-03-11 14:11 ` Qais Yousef
2020-03-11 14:00 ` Steven Rostedt [this message]
2020-03-11 14:23 ` Qais Yousef
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