Messages in this thread | | | Subject | Re: 5.6-rc3: WARNING: CPU: 48 PID: 17435 at kernel/sched/fair.c:380 enqueue_task_fair+0x328/0x440 | From | Dietmar Eggemann <> | Date | Thu, 5 Mar 2020 12:54:59 +0100 |
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On 05/03/2020 10:30, Vincent Guittot wrote: > Le mercredi 04 mars 2020 à 20:59:33 (+0100), Christian Borntraeger a écrit : >> >> On 04.03.20 20:38, Christian Borntraeger wrote: >>> >>> On 04.03.20 20:19, Dietmar Eggemann wrote:
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> Could you try to add the patch below on top of dietmar's one so we will have the status of > each level of the hierarchy ? > The 1st level seems ok but something wrong happens while walking the hierarchy > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 69fc30db7440..9ccde775e02e 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -5331,14 +5331,17 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) > > if (rq->tmp_alone_branch != &rq->leaf_cfs_rq_list) { > char path[64]; > + se = &p->se; > > - cfs_rq = cfs_rq_of(&p->se); > + for_each_sched_entity(se) { > + cfs_rq = cfs_rq_of(se); > > - sched_trace_cfs_rq_path(cfs_rq, path, 64); > + sched_trace_cfs_rq_path(cfs_rq, path, 64); > > - printk("CPU%d path=%s on_list=%d nr_running=%d p=[%s %d]\n", > - cpu_of(rq), path, cfs_rq->on_list, cfs_rq->nr_running, > + printk("CPU%d path=%s on_list=%d nr_running=%d throttled=%d p=[%s %d]\n", > + cpu_of(rq), path, cfs_rq->on_list, cfs_rq->nr_running, cfs_rq_throttled(cfs_rq), > p->comm, p->pid); > + } > } > > assert_list_leaf_cfs_rq(rq);
Yeah, that's better.
The fact that the task 'CPU 1/KVM' in 'machine-qemu\x2d16\x2dtest14.scope' hit the assert only tells us that some list_[add|\del]_leaf_cfs_rq on CPU62 before left rq->tmp_alone_branch != rq->leaf_cfs_rq_list.
I see that cgroup-v2 is used here.
>> [ 25.680326] CPU62 path=/machine.slice/machine-test.slice/machine-qemu\x2d16\x2dtest14. on_list=1 nr_running=1 p=[CPU 1/KVM 2543] >> [ 25.680334] ------------[ cut here ]------------ >> [ 25.680335] rq->tmp_alone_branch != &rq->leaf_cfs_rq_list >> [ 25.680351] WARNING: CPU: 61 PID: 2535 at kernel/sched/fair.c:380 enqueue_task_fair+0x3f6/0x4a8
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