linux-kernel - Re: [RFC][PATCH 2/4] sched: Push put_prev_task() into pick_next

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]

Date:	Fri, 15 Jun 2012 14:01:51 +0400
From:	Glauber Costa <glommer@...allels.com>
To:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
CC:	<mingo@...nel.org>, <pjt@...gle.com>, <venki@...gle.com>,
	<efault@....de>, <rostedt@...dmis.org>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [RFC][PATCH 2/4] sched: Push put_prev_task() into pick_next_task()

On 06/15/2012 02:03 PM, Peter Zijlstra wrote:
> On Fri, 2012-06-15 at 13:49 +0400, Glauber Costa wrote:
>> On 06/14/2012 05:29 PM, Peter Zijlstra wrote:
>>> +static struct task_struct *
>>> +pick_next_task_rt(struct rq *rq, struct task_struct *prev)
>>>    {
>>> -	struct task_struct *p = _pick_next_task_rt(rq);
>>> +	struct task_struct *p;
>>> +	struct rt_rq *rt_rq =&rq->rt;
>>> +
>>> +	if (!rt_rq->rt_nr_running)
>>> +		return NULL;
>>> +
>>> +	if (rt_rq_throttled(rt_rq))
>>> +		return NULL;
>>> +
>>> +	if (prev)
>>> +		prev->sched_class->put_prev_task(rq, prev);
>>> +
>> it might be me, but this one sounds strange. If the responsibility of
>> putting the task now lays with pic_next_task, you can't return NULL
>> without doing this first.
>
> Its the responsibility of the sched_class::pick_next_task implementation
> that will return the next task. Not of the first one called.
>
> Clearly this needs a comment.. /me adds.

hummmm, yeah, you are right. The comment does make it clearer.
--
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/