From: Mel Gorman <mel@csn.ul.ie>
To: Andrea Arcangeli <aarcange@redhat.com>
Cc: Shaohua Li <shaohua.li@intel.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm <linux-mm@kvack.org>,
"Chen, Tim C" <tim.c.chen@intel.com>
Subject: Re: too big min_free_kbytes
Date: Wed, 26 Jan 2011 15:23:02 +0000 [thread overview]
Message-ID: <20110126152302.GT18984@csn.ul.ie> (raw)
In-Reply-To: <20110126141746.GS18984@csn.ul.ie>
On Wed, Jan 26, 2011 at 02:17:46PM +0000, Mel Gorman wrote:
> On Mon, Jan 24, 2011 at 04:00:34PM +0100, Andrea Arcangeli wrote:
> > eOn Mon, Jan 24, 2011 at 11:56:46AM +0800, Shaohua Li wrote:
> > > Hi,
> > > With transparent huge page, min_free_kbytes is set too big.
> > > Before:
> > > Node 0, zone DMA32
> > > pages free 1812
> > > min 1424
> > > low 1780
> > > high 2136
> > > scanned 0
> > > spanned 519168
> > > present 511496
> > >
> > > After:
> > > Node 0, zone DMA32
> > > pages free 482708
> > > min 11178
> > > low 13972
> > > high 16767
> > > scanned 0
> > > spanned 519168
> > > present 511496
> > > This caused different performance problems in our test. I wonder why we
> > > set the value so big.
> >
> > It's to enable Mel's anti-frag that keeps pageblocks with movable and
> > unmovable stuff separated, same as "hugeadm
> > --set-recommended-min_free_kbytes".
> >
> > Now that I checked, I'm seeing quite too much free memory with only 4G
> > of ram... You can see the difference with a "cp /dev/sda /dev/null" in
> > background interleaving these two commands:
> >
>
> What kernel is this and is commit
> [99504748: mm: kswapd: stop high-order balancing when any suitable zone
> is balanced] present in the kernel you are testing?
>
> I'm having very little luck reproducing your scenario with
> 2.6.38-rc2.
Scratch that, a machine with 4G does reproduce it. The machine I was
trying was 2G. Will dig more.
--
Mel Gorman
Linux Technology Center
IBM Dublin Software Lab
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next prev parent reply other threads:[~2011-01-26 15:23 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-24 3:56 too big min_free_kbytes Shaohua Li
2011-01-24 15:00 ` Andrea Arcangeli
2011-01-25 14:35 ` Mel Gorman
2011-01-26 14:17 ` Mel Gorman
2011-01-26 15:23 ` Mel Gorman [this message]
2011-01-26 15:42 ` Andrea Arcangeli
2011-01-26 16:36 ` Mel Gorman
2011-01-26 17:42 ` Mel Gorman
2011-01-27 13:40 ` Mel Gorman
2011-01-27 15:27 ` Andrea Arcangeli
2011-01-27 16:03 ` Mel Gorman
2011-01-27 18:52 ` Andrea Arcangeli
2011-01-27 20:33 ` Rik van Riel
2011-01-27 21:31 ` Mel Gorman
2011-01-27 23:18 ` Rik van Riel
2011-01-28 10:35 ` Mel Gorman
2011-01-28 16:28 ` Andrea Arcangeli
2011-01-28 16:46 ` Mel Gorman
2011-01-28 17:16 ` Rik van Riel
2011-01-28 17:46 ` Andrea Arcangeli
2011-01-28 18:03 ` Rik van Riel
2011-01-28 18:24 ` Andrea Arcangeli
2011-01-28 19:34 ` Rik van Riel
2011-01-28 19:45 ` Andrea Arcangeli
2011-01-28 20:55 ` Rik van Riel
2011-01-29 19:45 ` Andrea Arcangeli
2011-01-28 17:34 ` Andrea Arcangeli
2011-01-28 17:10 ` Rik van Riel
2011-02-03 2:58 ` Andrea Arcangeli
2011-02-03 13:15 ` Mel Gorman
2011-02-03 18:59 ` Andrea Arcangeli
2011-02-03 14:36 ` Rik van Riel
2011-02-03 19:11 ` Andrea Arcangeli
2011-02-12 1:28 ` Simon Kirby
2011-02-14 2:25 ` Shaohua Li
2011-02-22 14:25 ` Mel Gorman
2011-02-22 14:42 ` Andrea Arcangeli
2011-02-22 14:50 ` Mel Gorman
2011-02-22 14:54 ` Andrea Arcangeli
2011-02-22 16:04 ` Mel Gorman
2011-02-22 16:40 ` Rik van Riel
2011-02-23 5:29 ` Shaohua Li
2011-02-23 14:45 ` Andrea Arcangeli
2011-02-24 8:08 ` Shaohua Li
2011-02-24 9:52 ` Mel Gorman
2011-02-24 9:57 ` Mel Gorman
2011-02-24 14:27 ` Andrea Arcangeli
2011-02-24 14:04 ` Andrea Arcangeli
2011-02-25 0:51 ` Shaohua Li
2011-02-25 12:13 ` Mel Gorman
2011-02-12 9:48 ` alex shi
2011-02-22 14:24 ` Mel Gorman
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