[PATCH v2 0/2] Fix SCHED_IDLE behavior on wakeup preemption

From: Abel Wu
Date: Thu Feb 27 2025 - 03:59:10 EST


The commit 6bc912b71b6f ("sched: SCHED_OTHER vs SCHED_IDLE isolation")
defines the behavior of SCHED_IDLE as following:

- no SCHED_IDLE buddies
- never let SCHED_IDLE preempt on wakeup
- always preempt SCHED_IDLE on wakeup
- limit SLEEPER fairness for SCHED_IDLE

and the middle two of them are broken now.

v2:
- Collect Reviewed-by tags from Vincent, Josh and Madadi, thanks!
- Rebased to up-to-date tip. (Madadi)
- Folded some discussion with Vincent into commit log.

Abel Wu (2):
sched/fair: Do not let idle entities preempt others
sched/fair: Fix premature check of WAKEUP_PREEMPTION

kernel/sched/fair.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

--
2.37.3