linux-kernel - Re: RFC [patch] sched,cgroup_sched: convince RT_GROUP

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1334461061.5751.15.camel@marge.simpson.net>
Date:	Sun, 15 Apr 2012 05:37:41 +0200
From:	Mike Galbraith <efault@....de>
To:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc:	LKML <linux-kernel@...r.kernel.org>, Ingo Molnar <mingo@...hat.com>
Subject: Re: RFC [patch] sched,cgroup_sched: convince RT_GROUP_SCHED
 throttle to work

On Sat, 2012-04-14 at 13:10 +0200, Peter Zijlstra wrote: 
> On Tue, 2012-04-10 at 11:08 +0200, Mike Galbraith wrote:
>  
> > --- a/kernel/sched/rt.c
> > +++ b/kernel/sched/rt.c
> > @@ -782,6 +782,19 @@ static int do_sched_rt_period_timer(stru
> >  	const struct cpumask *span;
> >  
> >  	span = sched_rt_period_mask();
> > +#ifdef CONFIG_RT_GROUP_SCHED
> > +	/*
> > +	 * FIXME: isolated CPUs should really leave the root task group,
> 
> No no, that's the wrong fix, the right fix is to remove isolcpus :-)

Yeah, isolcpus needs to die, but...

> I guess the alternative 'fix' is to not account the rt_runtime on
> isolated cpus.. does something like the below actually work?

I haven't tried it, because the exact same thing happens when you
isolate via cpusets directly below root.  One timer, two (or more)
rd->span, so _somebody_ is screwed.

-Mike

--
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/