linux-kernel - Re: [PATCH]sched/rt.c: Add reschedule to switched_from

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: <1354074344.6276.115.camel@gandalf.local.home>
Date:	Tue, 27 Nov 2012 22:45:44 -0500
From:	Steven Rostedt <rostedt@...dmis.org>
To:	Kirill Tkhai <tkhai@...dex.ru>
Cc:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH]sched/rt.c: Add reschedule to switched_from_rt()

On Fri, 2012-11-23 at 00:02 +0400, Kirill Tkhai wrote:
> Reschedule rq->curr if the first RT task has just been
> pulled to the rq.
> 
> Signed-off-by: Kirill V Tkhai <tkhai@...dex.ru>
> CC: Steven Rostedt <rostedt@...dmis.org>
> CC: Ingo Molnar <mingo@...nel.org>
> CC: Peter Zijlstra <peterz@...radead.org>
> ---
>  kernel/sched/rt.c |    7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
> index 418feb0..29bda5b 100644
> --- a/kernel/sched/rt.c
> +++ b/kernel/sched/rt.c
> @@ -1889,8 +1889,11 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p)
>  	 * we may need to handle the pulling of RT tasks
>  	 * now.
>  	 */
> -	if (p->on_rq && !rq->rt.rt_nr_running)
> -		pull_rt_task(rq);
> +	if (!p->on_rq || rq->rt.rt_nr_running)
> +		return;
> +
> +	if (pull_rt_task(rq))
> +		resched_task(rq->curr);

Wow really? We never set NEED_RESCHED after pulling an RT task to a
queue that is about to run SCHED_OTHER?

Hmm, this is usually called before switched_to(), and looking at
switched_to_fair() there's a good chance that it does it.

But anyway, might as well add it here, I don't think it will hurt. The
prio_changed_rt() does it.

Acked-by: Steven Rostedt <rostedt@...dmis.org>

-- Steve

>  }
>  
>  void init_sched_rt_class(void)


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/