Messages in this thread | | | From | Vincent Guittot <> | Date | Fri, 12 Nov 2021 08:50:46 +0100 | Subject | Re: printk deadlock due to double lock attempt on current CPU's runqueue |
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On Wed, 10 Nov 2021 at 20:50, Sultan Alsawaf <sultan@kerneltoast.com> wrote: > > On Wed, Nov 10, 2021 at 10:00:35AM +0100, Vincent Guittot wrote: > > Is it the same SCHED_WARN_ON(rq->tmp_alone_branch != > > &rq->leaf_cfs_rq_list); that generates the deadlock on v5.15 too ? > > > > one remaining tmp_alone_branch warning has been fixed in v5.15 with > > 2630cde26711 ("sched/fair: Add ancestors of unthrottled undecayed cfs_rq") > > I should clarify that I didn't actually reproduce the issue on v5.15; I just saw > that the call chain leading to the deadlock still existed in v5.15 after looking > through the code.
Thanks for the clarification
> > Failing the SCHED_WARN_ON(rq->tmp_alone_branch != &rq->leaf_cfs_rq_list); assert > is extremely rare in my experience, and I don't have a reproducer. It has only > happened once after months of heavy usage (with lots of reboots too, so not with > crazy high uptime). > > Sultan
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