linux-kernel - Re: [PATCH 5/7 v5] sched/fair: Add push task mechanism for EAS

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: <CAB8ipk8MY06Z+rwuA+FEaKqnwWjuf42VeBS5F98ww3tYttjPWw@mail.gmail.com>
Date: Wed, 16 Apr 2025 10:03:55 +0800
From: Xuewen Yan <xuewen.yan94@...il.com>
To: Vincent Guittot <vincent.guittot@...aro.org>
Cc: mingo@...hat.com, peterz@...radead.org, juri.lelli@...hat.com, 
	dietmar.eggemann@....com, rostedt@...dmis.org, bsegall@...gle.com, 
	mgorman@...e.de, vschneid@...hat.com, lukasz.luba@....com, 
	rafael.j.wysocki@...el.com, pierre.gondois@....com, 
	linux-kernel@...r.kernel.org, qyousef@...alina.io, hongyan.xia2@....com, 
	christian.loehle@....com, luis.machado@....com, qperret@...gle.com
Subject: Re: [PATCH 5/7 v5] sched/fair: Add push task mechanism for EAS

Hi Vincent,

On Tue, Apr 15, 2025 at 9:51 PM Vincent Guittot
<vincent.guittot@...aro.org> wrote:
>

> > I am carefully studying this series of patches. I have some doubts
> > about this part.
> >
> > Need we check the state?
> > READ_ONCE(p->__state) != TASK_RUNNING;
> > Because the tick will check it.
> >
> > On the other hand, need we check the sched_delayed?
> > Because it also checks it in put_prev_task_fair().
>
> In the case of tick, the task is the current task and the only one running
>

If the following occurs:
set_current_state(TASK_INTERRUPTIBLE);
schedule();
    __schedule();
        local_irq_disable();

the tick occurs between set_current_state() and local_irq_disable(),
maybe we do not need to migrate it.


BR
---
xuewen