From: Mike Galbraith <efault@gmx.de>
To: Nikhil Rao <ncrao@google.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <peterz@infradead.org>,
Venkatesh Pallipadi <venki@google.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/3][RFC] Improve load balancing when tasks have large weight differential
Date: Tue, 28 Sep 2010 15:57:53 +0200 [thread overview]
Message-ID: <1285682273.7469.3.camel@marge.simson.net> (raw)
In-Reply-To: <1285633798-26886-1-git-send-email-ncrao@google.com>
On Mon, 2010-09-27 at 17:29 -0700, Nikhil Rao wrote:
> Hi all,
>
> I have attached a series of patches that improve load balancing when there is a
> large weight differential between tasks. These patches are based off the
> feedback Peter Zijlstra gave in an earlier post (see http://thread.gmane.org/gmane.linux.kernel/1015966).
> They can be applied to v2.6.36-rc5 or -tip without conflicts.
>
> Tested with the following setup.
> - Test machine is a 16 cpu box (quad-socket, quad-core).
> - Baseline is v2.6.36-rc5 kernel
>
> We spawn 16 SCHED_IDLE soaker threads and one SCHED_NORMAL task. On the
> baseline kernel, the machine has ~18% idle time. With these patches applied on
> top of baseline, idle time drops to 0%.
Hm. I can get it stuck with one core idle on ym little quad.
top - 15:53:22 up 11 min, 17 users, load average: 5.05, 4.40, 2.51
Tasks: 270 total, 7 running, 263 sleeping, 0 stopped, 0 zombie
Cpu(s): 75.3%us, 0.0%sy, 0.0%ni, 24.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ P COMMAND
7455 root 5 -15 7996 340 256 R 100 0.0 0:59.93 1 pert
7421 root 20 0 7996 340 256 R 50 0.0 4:20.01 3 pert
7422 root 20 0 7996 340 256 R 50 0.0 3:45.81 2 pert
7423 root 20 0 7996 340 256 R 50 0.0 4:09.45 2 pert
7424 root 20 0 7996 344 256 R 50 0.0 4:12.75 3 pert
next prev parent reply other threads:[~2010-09-28 13:57 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-28 0:29 Nikhil Rao
2010-09-28 0:29 ` [PATCH 1/3] sched: set group_imb only a task can be pulled from the busiest cpu Nikhil Rao
2010-09-28 0:29 ` [PATCH 2/3] sched: drop group_capacity to 1 only if remote group has no running tasks Nikhil Rao
2010-09-28 23:04 ` Suresh Siddha
2010-10-11 21:20 ` Nikhil Rao
2010-09-28 0:29 ` [PATCH 3/3] sched: do not consider SCHED_IDLE tasks to be cache hot Nikhil Rao
2010-09-28 13:57 ` Mike Galbraith [this message]
2010-09-28 21:15 ` [PATCH 0/3][RFC] Improve load balancing when tasks have large weight differential Nikhil Rao
2010-09-29 1:45 ` Mike Galbraith
2010-09-29 19:32 ` Nikhil Rao
2010-10-04 3:08 ` Mike Galbraith
2010-10-06 8:23 ` Nikhil Rao
2010-10-08 7:22 ` Mike Galbraith
2010-10-08 20:34 ` Nikhil Rao
2010-10-10 10:15 ` Mike Galbraith
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