From: torbenh <torbenh@gmx.de>
To: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
Yong Zhang <yong.zhang0@gmail.com>,
bharata@linux.vnet.ibm.com, Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org, tglx@linutronix.de
Subject: Re: [patch] Re: autogroup: sched_setscheduler() fails
Date: Fri, 18 Feb 2011 14:40:50 +0100 [thread overview]
Message-ID: <20110218134050.GF3124@siel.b> (raw)
In-Reply-To: <1298033412.8735.30.camel@marge.simson.net>
On Fri, Feb 18, 2011 at 01:50:12PM +0100, Mike Galbraith wrote:
> On Fri, 2011-02-18 at 12:09 +0100, torbenh wrote:
> > On Tue, Feb 15, 2011 at 05:43:30PM +0100, Mike Galbraith wrote:
> > > On Tue, 2011-02-15 at 16:46 +0100, torbenh wrote:
> > > > On Mon, Jan 17, 2011 at 02:16:00PM +0100, Peter Zijlstra wrote:
> > > > > On Thu, 2011-01-13 at 04:54 +0100, Mike Galbraith wrote:
> > > > > > sched, autogroup: fix CONFIG_RT_GROUP_SCHED sched_setscheduler() failure.
> > > > > >
> > > > > > If CONFIG_RT_GROUP_SCHED is set, __sched_setscheduler() fails due to autogroup
> > > > > > not allocating rt_runtime. Free unused/unusable rt_se and rt_rq, redirect RT
> > > > > > tasks to the root task group, and tell __sched_setscheduler() that it's ok.
> > > > > >
> > > > > > Signed-off-by: Mike Galbraith <efault@gmx.de>
> > > > > > Reported-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
> > > > >
> > > > > Thanks, applied!
> > > >
> > > > while this behaviour is certeinly necessary, i think this is a hack.
> > > > it fixes the problem for autogroups.
> > > > But its not fixed for things which want to control the cfs shares via
> > > > normal cgroups.
> > >
> > > You mean automated control ala systemd? For a static set of groups, it
> > > works fine. I was wondering how systemd would deal with it.
> >
> > but i can not get the same behaviour as if CONFIG_RT_GROUP_SCHED was
> > off. iE N cgroups with different cpu.share values, but each with
> > rt_runtime_us=950000
>
> ? if CONFIG_RT_GROUP_SCHED was a noop, it wouldn't exist.
>
> > if the rt_runtime_us was in a different subsystem, its my understanding
> > that i could leave rt_runtime_us alone, and have all tasks in the root
> > group in the rt_runtime subsystem.
>
> Sounds like you just want to turn CONFIG_RT_GROUP_SCHED off.
>
> > > The allocation problem was shamelessly punted back to the user, where I
> > > think it truly belongs.
> >
> > sure it belongs to the user. but what if user wants to have different
> > cpu.shares, but full rt_runtime_us for all tasks ?
>
> Then the user doesn't want CONFIG_RT_GROUP_SCHED set.
many users dont configure their kernels themselves.
and this setting is not dynamic.
i guess its highly unlikely any normal user wants CONFIG_RT_GROUP_SCHED.
but maybe distros will turn it on.
--
torben Hohn
next prev parent reply other threads:[~2011-02-18 13:41 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-10 9:16 autogroup: sched_setscheduler() fails Bharata B Rao
2011-01-10 10:29 ` [patch] " Mike Galbraith
2011-01-10 10:59 ` Peter Zijlstra
2011-01-10 16:42 ` Mike Galbraith
2011-01-11 17:10 ` Bharata B Rao
2011-01-11 18:48 ` Mike Galbraith
2011-01-12 3:37 ` Bharata B Rao
2011-01-12 5:40 ` Yong Zhang
2011-01-12 6:35 ` Bharata B Rao
2011-01-12 7:24 ` Mike Galbraith
2011-01-12 8:06 ` Bharata B Rao
2011-01-12 8:47 ` Mike Galbraith
2011-01-12 9:26 ` Bharata B Rao
2011-01-12 6:17 ` Mike Galbraith
2011-01-12 6:42 ` Bharata B Rao
2011-01-12 5:40 ` Mike Galbraith
2011-01-12 6:32 ` Yong Zhang
2011-01-12 8:55 ` Mike Galbraith
2011-01-13 3:54 ` Mike Galbraith
2011-01-13 5:59 ` Yong Zhang
2011-01-13 6:02 ` Yong Zhang
2011-01-13 6:13 ` Mike Galbraith
2011-01-13 8:46 ` Bharata B Rao
2011-01-17 13:16 ` Peter Zijlstra
2011-02-15 15:46 ` torbenh
2011-02-15 16:43 ` Mike Galbraith
2011-02-18 11:09 ` torbenh
2011-02-18 12:50 ` Mike Galbraith
2011-02-18 13:40 ` torbenh [this message]
2011-02-22 12:24 ` torbenh
2011-02-22 14:47 ` Mike Galbraith
2011-02-28 17:53 ` torbenh
2011-02-28 18:29 ` Mike Galbraith
2011-02-28 19:10 ` torbenh
2011-03-01 4:02 ` Mike Galbraith
2011-03-01 4:21 ` Mike Galbraith
2011-03-01 15:59 ` torbenh
2011-01-18 19:05 ` [tip:sched/urgent] sched, autogroup: Fix CONFIG_RT_GROUP_SCHED sched_setscheduler() failure tip-bot for Mike Galbraith
2011-01-12 5:43 ` [patch] Re: autogroup: sched_setscheduler() fails Yong Zhang
2011-01-12 6:25 ` Mike Galbraith
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