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From: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
To: Michael Wang <wangyun@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Ingo Molnar <mingo@elte.hu>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v5] sched: Avoid unnecessary work in reweight_entity
Date: Mon, 27 Feb 2012 09:42:59 +0530	[thread overview]
Message-ID: <20120227041259.GA2331@linux.vnet.ibm.com> (raw)
In-Reply-To: <4F48E882.6090409@linux.vnet.ibm.com>

* Michael Wang <wangyun@linux.vnet.ibm.com> [2012-02-25 21:56:18]:

> Hi, Peter
> 
> I have collected more testing data, here is the test results:
> 
> Machine:	ThinkPad T420
> OS:		Ubuntu 11.10
> Benchmark:	time make -j14 (build kernel)

Is that benchmark run in root (cpu) cgroup? If so, reweight_entity() should not
kick in at all.

static void update_cfs_shares(struct cfs_rq *cfs_rq)
{

        ..

        if (!se || throttled_hierarchy(cfs_rq))
                return;

        ..

	reweight_entity();
}

If you want to stress reweight_entity() create several (cpu) cgroups
and launch workload like kernbench in each of them ..

- vatsa


  reply	other threads:[~2012-02-27  4:13 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-02-06  9:37 [PATCH] sched: Avoid unnecessary work in reweight_entity Michael Wang
2012-02-06 10:31 ` Michael Wang
2012-02-07  2:18 ` Michael Wang
2012-02-07  2:36   ` [PATCH v2] " Michael Wang
2012-02-08  2:10     ` [PATCH v3] sched: " Michael Wang
2012-02-16 14:14       ` [PATCH v4] " Michael Wang
2012-02-16 14:29         ` Peter Zijlstra
2012-02-17  2:28           ` Michael Wang
2012-02-17  6:03           ` [PATCH v5] " Michael Wang
2012-02-18  1:43             ` Michael Wang
2012-02-20 13:08               ` Peter Zijlstra
2012-02-23 10:40                 ` Michael Wang
2012-02-24  2:08                   ` Michael Wang
2012-02-25 13:56                     ` Michael Wang
2012-02-27  4:12                       ` Srivatsa Vaddagiri [this message]
2012-02-27  5:07                         ` Michael Wang
2012-02-27  5:10                           ` Srivatsa Vaddagiri
2012-02-27  6:21                             ` Michael Wang
2012-02-27  6:44                               ` Srivatsa Vaddagiri
2012-02-16 14:32         ` [PATCH v4] " Michael Wang

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