linux-kernel - Re: [PATCH 1/2] sched: Drop the need_resched() loop from cond

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: <20090710152425.GB5318@nowhere>
Date:	Fri, 10 Jul 2009 17:24:27 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Arnd Bergmann <arnd@...db.de>
Cc:	Ingo Molnar <mingo@...e.hu>, LKML <linux-kernel@...r.kernel.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>
Subject: Re: [PATCH 1/2] sched: Drop the need_resched() loop from
	cond_resched()

On Fri, Jul 10, 2009 at 05:17:38PM +0200, Arnd Bergmann wrote:
> On Friday 10 July 2009, Frederic Weisbecker wrote:
> > --- a/kernel/sched.c
> > +++ b/kernel/sched.c
> > @@ -6613,11 +6613,9 @@ static void __cond_resched(void)
> >          * PREEMPT_ACTIVE, which could trigger a second
> >          * cond_resched() call.
> >          */
> > -       do {
> > -               add_preempt_count(PREEMPT_ACTIVE);
> > -               schedule();
> > -               sub_preempt_count(PREEMPT_ACTIVE);
> > -       } while (need_resched());
> > +       add_preempt_count(PREEMPT_ACTIVE);
> > +       schedule();
> > +       sub_preempt_count(PREEMPT_ACTIVE);
> >  }
> >  
> 
> If you drop the loop, then you should also remove the comment that
> explains why it was put there.
> 
> 	Arnd <><

Hmm, these comments seem to actually explain why we do the PREEMPT_ACTIVE
trick, which is to prevent from cond_resched() recursion, right?

--
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/