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From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Huang Ying <ying.huang@intel.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	David Howells <dhowells@redhat.com>,
	linux-kernel@vger.kernel.org, lkp@linux.intel.com
Subject: Re: aim7 performance regression by commit 5a50508 report from LKP
Date: Fri, 1 Feb 2013 18:53:13 +0800	[thread overview]
Message-ID: <20130201105313.GA22784@yliu-dev.sh.intel.com> (raw)
In-Reply-To: <20130131112252.GB4587@gmail.com>

On Thu, Jan 31, 2013 at 12:22:52PM +0100, Ingo Molnar wrote:
> 
> * Yuanhan Liu <yuanhan.liu@linux.intel.com> wrote:
> 
> > > or whether the lock hold times could be reduced drastically
> > 
> > I also found one, but it doesn't sound like the one will 
> > reduce lock hold times drastically:
> >
> >    vma_lock_anon_vma() seems covered too much code at
> >    expand_up/downwards.
> > 
> > Well, again, it's quite a tiny optimization for reducing the 
> > coverage.
> 
> The fundamental problem is I think that there's a single anon 
> vma lock for the whole workload, right?

Yes.
> 
> Is that really fundamentally needed, could that be spread out 
> perhaps?

I'm digging into this. 

Thanks.

	--yliu
> 
> ( But first we want to see how much of the regression we can fix 
>   in an equivalent-locking-patterns fashion - improving locking
>   is a separate matter. )
> 
> Thanks,
> 
> 	Ingo

      reply	other threads:[~2013-02-01 10:52 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-29  8:25 Yuanhan Liu
2013-01-29  8:44 ` Ingo Molnar
2013-01-29  9:06   ` Yuanhan Liu
2013-01-29  9:12     ` Ingo Molnar
2013-01-30  9:34       ` Yuanhan Liu
2013-01-31 11:22         ` Ingo Molnar
2013-02-01 10:53           ` Yuanhan Liu [this message]

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