Messages in this thread | | | Date | Wed, 10 Nov 2021 11:50:30 -0800 | From | Sultan Alsawaf <> | Subject | Re: printk deadlock due to double lock attempt on current CPU's runqueue |
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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.
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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