From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH v8 7/8] sched/core: Prevent race condition between cpuset
 and __sched_setscheduler()
Date: Mon, 1 Jul 2019 21:11:41 +0200
Message-ID: <20190701191141.GD3402@hirez.programming.kicks-ass.net>
References: <20190628080618.522-1-juri.lelli@redhat.com>
 <20190628080618.522-8-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 10:06:17AM +0200, Juri Lelli wrote:
> No synchronisation mechanism exists between the cpuset subsystem and
> calls to function __sched_setscheduler(). As such, it is possible that
> new root domains are created on the cpuset side while a deadline
> acceptance test is carried out in __sched_setscheduler(), leading to a
> potential oversell of CPU bandwidth.
> 
> Grab cpuset_rwsem read lock from core scheduler, so to prevent
> situations such as the one described above from happening.
> 

ISTR there being a funny vs normalize_rt_tasks(); maybe mention that?