linux-kernel - Re: [PATCH v3 4/5] sched/fair: Fix use of find_idlest

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20170831135440.t5mhrhuofudxlgy4@destiny>
Date:   Thu, 31 Aug 2017 09:54:40 -0400
From:   Josef Bacik <josef@...icpanda.com>
To:     Brendan Jackman <brendan.jackman@....com>
Cc:     Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        linux-kernel@...r.kernel.org,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Josef Bacik <josef@...icpanda.com>,
        Morten Rasmussen <morten.rasmussen@....com>
Subject: Re: [PATCH v3 4/5] sched/fair: Fix use of find_idlest_group when no
 groups are allowed

On Thu, Aug 31, 2017 at 12:58:01PM +0100, Brendan Jackman wrote:
> When p is allowed on none of the CPUs in the sched_domain, we
> currently return NULL from find_idlest_group, and pointlessly
> continue the search on lower sched_domain levels (where p is also not
> allowed) before returning prev_cpu regardless (as we have not updated
> new_cpu).
> 
> Add an explicit check for this case, and a comment to
> find_idlest_group. Now when find_idlest_group returns NULL, it always
> means that the local group is allowed and idlest.
> 

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

Thanks,

Josef