From: Peter Zijlstra <peterz@infradead.org>
To: Dima Zavin <dima@android.com>
Cc: linux-kernel@vger.kernel.org, "Ingo Molnar" <mingo@elte.hu>,
"Mike Galbraith" <efault@gmx.de>,
"Arve Hjønnevåg" <arve@android.com>
Subject: Re: [PATCH 1/2] sched: normalize sleeper's vruntime during group change
Date: Fri, 01 Oct 2010 13:59:28 +0200 [thread overview]
Message-ID: <1285934368.2144.60.camel@laptop> (raw)
In-Reply-To: <AANLkTikVQist_VnCcpZzU78t0TVuocwOcDPG4POVzSdv@mail.gmail.com>
On Thu, 2010-09-30 at 12:14 -0700, Dima Zavin wrote:
>
> > Please explain this stuff..
>
> The situation today is quite bad for sleeping tasks. Currently, when
> you move a sleeping thread between cgroups, the thread can retain its
> old vruntime value if the old group was far ahead of the new group
> since it essentially does a max(se->vruntime, new_vruntime) in
> place_entity. This can prevent the task from running for a very long
> time. That is what this patch was trying to address. It normalizes the
> sleeper thread's vruntime before moving it to the new group.
>
>
Hrm,.. ok, I tend to not use this cgroup gunk more that I absolutely
have to, so I'll take your word for it.
But doesn't normal cross-cpu task migration already solve this problem?
Therefore wouldn't it be possible to adapt/extend that code to also deal
with this particular issue?
It would avoid growing more cgroup fudge..
next prev parent reply other threads:[~2010-10-01 11:59 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-29 6:46 [PATCH 1/2] sched: normalize sleeper's vruntime during group change Dima Zavin
2010-09-29 6:46 ` [PATCH 2/2] sched: use the old min_vruntime when normalizing on dequeue Dima Zavin
2010-10-07 21:00 ` Dima Zavin
2010-10-08 6:57 ` Mike Galbraith
2010-09-29 6:54 ` [PATCH 1/2] sched: normalize sleeper's vruntime during group change Pekka Enberg
2010-09-29 7:17 ` Dima Zavin
2010-09-29 8:13 ` Mike Galbraith
2010-09-29 19:02 ` Dima Zavin
2010-09-29 21:44 ` Dima Zavin
2010-09-30 10:47 ` Peter Zijlstra
2010-09-30 19:14 ` Dima Zavin
2010-10-01 11:59 ` Peter Zijlstra [this message]
2010-10-04 19:18 ` Dima Zavin
2010-10-06 22:56 ` Dima Zavin
2010-10-07 2:24 ` Mike Galbraith
2010-10-15 13:50 ` Peter Zijlstra
2010-10-22 13:02 ` [tip:sched/urgent] sched, cgroup: Fixup broken cgroup movement tip-bot for Peter Zijlstra
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