On Tue, Jan 28, 2025 at 12:46:07PM +0100, Mike Galbraith wrote: > Seems 6.13 is gripe free thanks to it containing 4423af84b297. > > I stumbled upon a reproducer for my x86_64 desktop box: all I need do > is fire up a kvm guest in an enterprise configured host. That inspires > libvirt goop to engage group scheduling, splat follows instantly. > > Back 4423af84b297 out of 6.13, it starts griping, add it to a 6.12 tree > containing 6d71a9c61604, it stops doing so. Ooh, does something like the below (+- reverse-renames as applicable to .12) also help? --- diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b67222dea491..8766f7d3d297 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3781,6 +3781,7 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, update_entity_lag(cfs_rq, se); se->deadline -= se->vruntime; se->rel_deadline = 1; + cfs_rq->nr_queued--; if (!curr) __dequeue_entity(cfs_rq, se); update_load_sub(&cfs_rq->load, se->load.weight); @@ -3811,6 +3812,7 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, place_entity(cfs_rq, se, 0); if (!curr) __enqueue_entity(cfs_rq, se); + cfs_rq->nr_queued++; /* * The entity's vruntime has been adjusted, so let's check
