[PATCH 0/4] sched/fair: fixes in presence of lot of sched_idle tasks

Vincent Guittot
2022-08-25T12:27:36Z

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(-)

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2.17.1