Date: Thu, 31 Aug 2017 09:54:59 -0400
From: Josef Bacik <josef@toxicpanda.com>
To: Brendan Jackman <brendan.jackman@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>, Peter Zijlstra <peterz@infradead.org>,
        linux-kernel@vger.kernel.org,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Josef Bacik <josef@toxicpanda.com>,
        Morten Rasmussen <morten.rasmussen@arm.com>
Subject: Re: [PATCH v3 5/5] sched/fair: Fix use of find_idlest_group when
 local group is idlest
Message-ID: <20170831135459.ilgktukuchws2kny@destiny>
References: <20170831115802.26365-1-brendan.jackman@arm.com>
 <20170831115802.26365-6-brendan.jackman@arm.com>
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On Thu, Aug 31, 2017 at 12:58:02PM +0100, Brendan Jackman wrote:
> find_idlest_group returns NULL when the local group is idlest. The
> caller then continues the find_idlest_group search at a lower level
> of the current CPU's sched_domain hierarchy. find_idlest_group_cpu is
> not consulted and, crucially, @new_cpu is not updated. This means the
> search is pointless and we return @prev_cpu from select_task_rq_fair.
> 
> This is fixed by initialising @new_cpu to @cpu instead of
> @prev_cpu.
> 

Reviewed-by: Josef Bacik <jbacik@fb.com>

Thanks,

Josef