From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH v8 8/8] rcu/tree: Setschedule gp ktread to SCHED_FIFO
 outside of atomic region
Date: Mon, 1 Jul 2019 21:13:08 +0200
Message-ID: <20190701191308.GE3402@hirez.programming.kicks-ass.net>
References: <20190628080618.522-1-juri.lelli@redhat.com>
 <20190628080618.522-9-juri.lelli@redhat.com>
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To: Juri Lelli <juri.lelli@redhat.com>
Cc: mingo@redhat.com, rostedt@goodmis.org, tj@kernel.org, linux-kernel@vger.kernel.org, luca.abeni@santannapisa.it, claudio@evidence.eu.com, tommaso.cucinotta@santannapisa.it, bristot@redhat.com, mathieu.poirier@linaro.org, lizefan@huawei.com, cgroups@vger.kernel.org

On Fri, Jun 28, 2019 at 10:06:18AM +0200, Juri Lelli wrote:
> sched_setscheduler() needs to acquire cpuset_rwsem, but it is currently
> called from an invalid (atomic) context by rcu_spawn_gp_kthread().
> 
> Fix that by simply moving sched_setscheduler_nocheck() call outside of
> the atomic region, as it doesn't actually require to be guarded by
> rcu_node lock.

Maybe move this earlier in the series such that the bug doesn't manifest
in bisection?