Messages in this thread Patch in this message | | | Date | Fri, 10 Jul 2009 17:05:16 -0700 (PDT) | From | Paul Turner <> | Subject | Bug in SCHED_IDLE interaction with group scheduling? |
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Hi Peter,
It seems like there's an assumption in the sched_idle policy check in place_entity that the sched_entity we are looking at belongs to a task?
- Paul
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sched: bug in SCHED_IDLE interaction with group scheduling
One of the isolation modifications for SCHED_IDLE is the unitization of sleeper credit. However the check for this assumes that the sched_entity we're placing always belongs to a task.
This is potentially not true with group scheduling and leaves us rummaging randomly when we try to pull the policy.
Signed-off-by: Paul Turner <pjt@google.com> --- kernel/sched_fair.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index ba7fd6e..7c248dc 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -687,7 +687,8 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial) * all of which have the same weight. */ if (sched_feat(NORMALIZED_SLEEPER) && - task_of(se)->policy != SCHED_IDLE) + (!entity_is_task(se) || + task_of(se)->policy != SCHED_IDLE)) thresh = calc_delta_fair(thresh, se); vruntime -= thresh; -- 1.5.4.3
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