From: Cong Wang <xiyou.wangcong@gmail.com>
To: Michael Wang <wangyun@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Xiaotian Feng <xtfeng@gmail.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2] sched: Accelerate "pick_next_entity" under special condition
Date: Mon, 30 Jan 2012 11:25:34 +0800 [thread overview]
Message-ID: <4F260DAE.4000008@gmail.com> (raw)
In-Reply-To: <4F260BFE.2070503@linux.vnet.ibm.com>
On 01/30/2012 11:18 AM, Michael Wang wrote:
> But the sched.o under ./arch/x86/kernel/cpu/ still not change...
> I think I may checking the wrong file, because this patch is for fair.c.
>
> And the fair.o changed after apply the patch, the size is a little
> bigger, and the gcc generated code changed.
>
> But I still don't know what can we get from this result? Bigger size is
> caused by additional code, but these additional code will help to step
> over some unnecessary code under special condition, looks like some
> balance between size and performance...
As your patch reduces the conditionals from 24 to 14, so it is possible
that it also reduces the size of the code too. This is Ingo's point.
You need to check the diff to see why gcc actually generates bigger code.
next prev parent reply other threads:[~2012-01-30 3:25 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-16 9:37 [PATCH] sched: Accelerate "pick_next_entity" under special condition Michael Wang
2012-01-16 9:50 ` Michael Wang
2012-01-16 9:51 ` Peter Zijlstra
2012-01-16 10:34 ` Michael Wang
2012-01-17 2:36 ` [PATCH v2] " Michael Wang
2012-01-17 2:41 ` Michael Wang
2012-01-17 2:58 ` Xiaotian Feng
2012-01-17 3:04 ` Michael Wang
2012-01-25 15:55 ` Peter Zijlstra
2012-01-26 10:04 ` Ingo Molnar
2012-01-27 1:22 ` Michael Wang
2012-01-27 4:42 ` Cong Wang
2012-01-29 6:32 ` Michael Wang
2012-01-29 16:33 ` Ingo Molnar
2012-01-30 3:18 ` Michael Wang
2012-01-30 3:25 ` Cong Wang [this message]
2012-01-30 5:47 ` Michael Wang
2012-07-03 6:34 ` [PATCH] sched: remove useless code in yield_to Michael Wang
2012-07-12 5:45 ` Michael Wang
2012-07-12 14:07 ` Peter Zijlstra
2012-07-12 18:44 ` Mike Galbraith
2012-07-16 2:39 ` Michael Wang
2012-08-17 6:56 ` Michael Wang
2012-08-17 9:43 ` Peter Zijlstra
2012-08-10 3:05 ` Michael Wang
2012-08-10 3:10 ` Michael Wang
2012-08-10 5:52 ` Mike Galbraith
2012-09-04 18:50 ` [tip:sched/core] sched: Remove useless code in yield_to() tip-bot for Michael Wang
2012-01-27 0:56 ` [PATCH v2] sched: Accelerate "pick_next_entity" under special condition Michael Wang
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