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From:   Vincent Guittot <vincent.guittot@linaro.org>
To:     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, vschneid@redhat.com,
        linux-kernel@vger.kernel.org
Cc:     zhangqiao22@huawei.com,
        Vincent Guittot <vincent.guittot@linaro.org>
Subject: [PATCH 0/4] sched/fair: fixes in presence of lot of sched_idle tasks
Date:   Thu, 25 Aug 2022 14:27:22 +0200
Message-Id: <20220825122726.20819-1-vincent.guittot@linaro.org>
Precedence: bulk

This patchset gathers somes cleanups but also improvements and fixes for
scheduling UCs that involved a lot of sched_idle tasks. In such case, the
sched_idle tasks impact significantly the behavior of other tasks whereas
they should not. These patches don't impact other "normal" UCs.

 have foudn these changes while studying Zhang's problem [1] but AFAICT,
 these patches don't fix his problem.

[1] https://lore.kernel.org/lkml/20220810015636.3865248-1-zhangsong34@huawei.com/

Vincent Guittot (4):
  sched/fair: make sure to try to detach at least one movable task
  sched/fair: cleanup loop_max and loop_break
  sched/fair: move call to list_last_entry() in detach_tasks
  sched/fair: limit sched slice duration

 kernel/sched/core.c  |  6 +-----
 kernel/sched/fair.c  | 29 +++++++++++++++++------------
 kernel/sched/sched.h |  6 ++++++
 3 files changed, 24 insertions(+), 17 deletions(-)

-- 
2.17.1