From: Mel Gorman <mgorman@suse.de>
To: Huang Ying <ying.huang@linux.intel.com>
Cc: LKML <linux-kernel@vger.kernel.org>, LKP ML <lkp@01.org>
Subject: Re: [LKP] [mm] 3484b2de949: -46.2% aim7.jobs-per-min
Date: Sat, 28 Feb 2015 01:46:42 +0000 [thread overview]
Message-ID: <20150228014642.GG3087@suse.de> (raw)
In-Reply-To: <1425021696.10337.55.camel@linux.intel.com>
On Fri, Feb 27, 2015 at 03:21:36PM +0800, Huang Ying wrote:
> FYI, we noticed the below changes on
>
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> commit 3484b2de9499df23c4604a513b36f96326ae81ad ("mm: rearrange zone fields into read-only, page alloc, statistics and page reclaim lines")
>
> The perf cpu-cycles for spinlock (zone->lock) increased a lot. I suspect there are some cache ping-pong or false sharing.
>
Are you sure about this result? I ran similar tests here and found that
there was a major regression introduced near there but it was commit
05b843012335 ("mm: memcontrol: use root_mem_cgroup res_counter") that
cause the problem and it was later reverted. On local tests on a 4-node
machine, commit 3484b2de9499df23c4604a513b36f96326ae81ad was within 1%
of the previous commit and well within the noise.
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2015-02-28 1:46 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-27 7:21 [LKP] [mm] 3484b2de949: -46.2% aim7.jobs-per-min Huang Ying
2015-02-27 11:53 ` Mel Gorman
2015-02-28 1:24 ` Huang Ying
2015-02-28 7:57 ` Huang Ying
2015-02-28 1:46 ` Mel Gorman [this message]
2015-02-28 2:30 ` Huang Ying
2015-02-28 2:42 ` Huang Ying
2015-02-28 7:30 ` Huang Ying
2015-03-05 5:34 ` Huang Ying
2015-03-05 10:26 ` Mel Gorman
2015-03-23 8:46 ` Huang Ying
2015-03-25 10:54 ` Mel Gorman
2015-03-27 8:49 ` Huang Ying
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