From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juri Lelli Subject: Re: [PATCH v8 8/8] rcu/tree: Setschedule gp ktread to SCHED_FIFO outside of atomic region Date: Tue, 2 Jul 2019 09:01:28 +0200 Message-ID: <20190702070128.GG26005@localhost.localdomain> References: <20190628080618.522-1-juri.lelli@redhat.com> <20190628080618.522-9-juri.lelli@redhat.com> <20190701191308.GE3402@hirez.programming.kicks-ass.net> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <20190701191308.GE3402@hirez.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Peter Zijlstra 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 01/07/19 21:13, Peter Zijlstra wrote: > 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? OK.