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Date:   Mon, 16 Aug 2021 14:31:09 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Josh Don <joshdon@google.com>
Cc:     Ingo Molnar <mingo@redhat.com>, Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        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>,
        Paul Turner <pjt@google.com>,
        Oleg Rombakh <olegrom@google.com>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Steve Sistare <steven.sistare@oracle.com>,
        Tejun Heo <tj@kernel.org>, Rik van Riel <riel@surriel.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] sched: adjust SCHED_IDLE interactions
Message-ID: <YRpajXKCPiPEHFAV@hirez.programming.kicks-ass.net>
References: <20210730020019.1487127-1-joshdon@google.com>
 <20210730020019.1487127-3-joshdon@google.com>
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On Thu, Jul 29, 2021 at 07:00:19PM -0700, Josh Don wrote:
> 1) Ignore min_granularity for determining the sched_slide of a
> SCHED_IDLE entity when it is competing with a non SCHED_IDLE entity.
> This reduces the latency of getting a non SCHED_IDLE entity back on cpu,
> at the expense of increased context switch frequency of SCHED_IDLE
> entities.

> 2) Don't give sleeper credit to SCHED_IDLE entities when they wake onto
> a cfs_rq with non SCHED_IDLE entities. As a result, newly woken
> SCHED_IDLE entities will take longer to preempt non SCHED_IDLE entities.

ISTR we had a rule about one change per patch :-)