On Mon, 2024-09-16 at 12:00 +0530, Venkat Rao Bagalkote wrote:
Greetings!!!Greetings,
I am seeing below kernel crash from 6.11.0-rc4-next-20240820.I met this, as well as other ways the wheels can fall off that turned
Tried to do git bisect, but it didnt point to right patch. Attached is
the bisect log.
Any help in fixing this is much appriciated.
out to have the same root. I gave Peter a heads up with diag offline,
but having now convinced myself that all is well, I'll go ahead and
post a patchlet.
At the very least it's worth putting out for wider testing.. and should
anyone have something prettier in mind, yeah, do that instead.
sched: Fix sched_delayed vs cfs_bandwidth
Meeting an unfinished DELAY_DEQUEUE treated entity in unthrottle_cfs_rq()
leads to a couple terminal scenarios. Finish it first, so ENQUEUE_WAKEUP
can proceed as it would have sans DELAY_DEQUEUE treatment.
Fixes: 152e11f6df29 ("sched/fair: Implement delayed dequeue")
Signed-off-by: Mike Galbraith <efault@xxxxxx>
---
kernel/sched/fair.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6049,10 +6049,14 @@ void unthrottle_cfs_rq(struct cfs_rq *cf
for_each_sched_entity(se) {
struct cfs_rq *qcfs_rq = cfs_rq_of(se);
- if (se->on_rq) {
- SCHED_WARN_ON(se->sched_delayed);
- break;
+ /* Handle any unfinished DELAY_DEQUEUE business first. */
+ if (unlikely(se->on_rq && se->sched_delayed)) {
+ int flags = DEQUEUE_SLEEP | DEQUEUE_SPECIAL;
+
+ dequeue_entity(qcfs_rq, se, flags | DEQUEUE_DELAYED);
}
+ if (se->on_rq)
+ break;
enqueue_entity(qcfs_rq, se, ENQUEUE_WAKEUP);
if (cfs_rq_is_idle(group_cfs_rq(se)))