linux-kernel - Re: [PATCH 1/2] sched/fair: optimization of update_blocked

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: <CAKfTPtB9EzuHQ+K56EbDSUV6ifkpj2OR12tXRBN6=NQDwC2OMg@mail.gmail.com>
Date:   Fri, 8 Feb 2019 16:44:53 +0100
From:   Vincent Guittot <vincent.guittot@...aro.org>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     linux-kernel <linux-kernel@...r.kernel.org>,
        Ingo Molnar <mingo@...hat.com>, Tejun Heo <tj@...nel.org>,
        Sargun Dhillon <sargun@...gun.me>,
        Xie XiuQi <xiexiuqi@...wei.com>, xiezhipeng1@...wei.com,
        Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [PATCH 1/2] sched/fair: optimization of update_blocked_averages()

On Fri, 8 Feb 2019 at 16:40, Peter Zijlstra <peterz@...radead.org> wrote:
>
>
> Argh head hurts!!
>
> On Wed, Feb 06, 2019 at 05:14:21PM +0100, Vincent Guittot wrote:
> > @@ -4438,6 +4450,10 @@ static int tg_unthrottle_up(struct task_group *tg, void *data)
> >               /* adjust cfs_rq_clock_task() */
> >               cfs_rq->throttled_clock_task_time += rq_clock_task(rq) -
> >                                            cfs_rq->throttled_clock_task;
> > +
> > +             /* Add cfs_rq with already running entity in the list */
> > +             if (cfs_rq->nr_running >= 1)
> > +                     list_add_leaf_cfs_rq(cfs_rq);
> >       }
> >
> >       return 0;
>
> Do we want the below to go with the above change?
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 38d4669aa2ef..0bd80a891025 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -4536,6 +4536,8 @@ void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
>         /* update hierarchical throttle state */
>         walk_tg_tree_from(cfs_rq->tg, tg_nop, tg_unthrottle_up, (void *)rq);
>
> +       assert_list_leaf_cfs_rq(rq);
> +

Good point but this should go after the for_each_sched_entity() loop

>         if (!cfs_rq->load.weight)
>                 return;
>