From: "Robert Mueller" <robm@fastmail.fm>
To: Shaohua Li <shaohua.li@intel.com>
Cc: Christoph Lameter <cl@linux.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Bron Gondwana <brong@fastmail.fm>, linux-mm <linux-mm@kvack.org>,
Mel Gorman <mel@csn.ul.ie>
Subject: Re: Default zone_reclaim_mode = 1 on NUMA kernel is bad for file/email/web servers
Date: Fri, 17 Sep 2010 17:32:36 +1000 [thread overview]
Message-ID: <1284708756.2702.1395472601@webmail.messagingengine.com> (raw)
In-Reply-To: <1284703264.3408.1.camel@sli10-conroe.sh.intel.com>
> > I don't think this is any fault of how the software works. It's a
> > *very* standard "pre-fork child processes, allocate incoming
> > connections to a child process, open and mmap one or more files to
> > read data from them". That's not exactly a weird programming model,
> > and it's bad that the kernel is handling that case very badly with
> > everything default.
>
> maybe you incoming connection always happen on one CPU and you do the
> page allocation in that cpu, so some nodes use out of memory but
> others have a lot free. Try bind the child process to different nodes
> might help.
There's are 5000+ child processes (it's a cyrus IMAP server). Neither
the parent of any of the children are bound to any particular CPU. It
uses a standard fcntl lock to make sure only one spare child at a time
calls accept(). I don't think that's the problem.
Rob
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next prev parent reply other threads:[~2010-09-17 7:32 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1284349152.15254.1394658481@webmail.messagingengine.com>
2010-09-16 10:01 ` Default zone_reclaim_mode = 1 on NUMA kernel is bad for file/email/web servers KOSAKI Motohiro
2010-09-16 17:06 ` Christoph Lameter
2010-09-17 0:50 ` Robert Mueller
2010-09-17 6:01 ` Shaohua Li
2010-09-17 7:32 ` Robert Mueller [this message]
2010-09-17 13:56 ` Christoph Lameter
2010-09-17 14:09 ` Bron Gondwana
2010-09-17 14:22 ` Christoph Lameter
2010-09-17 23:01 ` Bron Gondwana
2010-09-20 9:34 ` Mel Gorman
2010-09-20 23:41 ` Default zone_reclaim_mode = 1 on NUMA kernel is bad forfile/email/web servers Rob Mueller
2010-09-21 9:04 ` Mel Gorman
2010-09-21 14:14 ` Christoph Lameter
2010-09-22 3:44 ` Rob Mueller
2010-09-27 2:01 ` KOSAKI Motohiro
2010-09-27 13:53 ` Christoph Lameter
2010-09-27 23:17 ` Robert Mueller
2010-09-28 12:35 ` Christoph Lameter
2010-09-28 12:42 ` Bron Gondwana
2010-09-28 12:49 ` Christoph Lameter
2010-09-30 7:05 ` Andi Kleen
2010-10-04 12:45 ` KOSAKI Motohiro
2010-10-04 13:07 ` Christoph Lameter
2010-10-05 5:32 ` KOSAKI Motohiro
2010-10-04 19:43 ` David Rientjes
2010-09-21 1:05 ` Default zone_reclaim_mode = 1 on NUMA kernel is bad for file/email/web servers KAMEZAWA Hiroyuki
2010-09-27 2:04 ` KOSAKI Motohiro
2010-09-27 2:06 ` KAMEZAWA Hiroyuki
2010-09-23 11:44 ` Balbir Singh
2010-09-30 8:38 ` Bron Gondwana
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