From: Mel Gorman <mgorman@suse.de>
To: Christoph Lameter <cl@linux.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Minchan Kim <minchan.kim@gmail.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] mm: page allocator: Initialise ZLC for first zone eligible for zone_reclaim
Date: Wed, 20 Jul 2011 20:18:58 +0100 [thread overview]
Message-ID: <20110720191858.GO5349@suse.de> (raw)
In-Reply-To: <alpine.DEB.2.00.1107201307530.1472@router.home>
On Wed, Jul 20, 2011 at 01:08:46PM -0500, Christoph Lameter wrote:
> Hmmm... Looking at get_page_from_freelist and considering speeding that up
> in general: Could we move the whole watermark logic into the slow path?
> Only check when we refill the per cpu queues?
Each CPU list can hold 186 pages (on my currently running
kernel at least) which is 744K. As I'm running with THP enabled,
the min watermark is 25852K so with 34 of more CPUs, there is a
risk that a zone would be fully depleted due to lack of watermark
checking. Bit unlikely that 34 CPUs would be on one node but the risk
is there. Without THP, the min watermark would have been something like
32K where it would be much easier to accidentally consume all memory.
Yes, moving the watermark checks to the slow path would be faster
but under some conditions, the system will lock up.
--
Mel Gorman
SUSE Labs
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2011-07-20 19:19 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-15 15:08 [PATCH 0/2] Reduce frequency of stalls due to zone_reclaim() on NUMA v2r1 Mel Gorman
2011-07-15 15:08 ` [PATCH 1/2] mm: page allocator: Initialise ZLC for first zone eligible for zone_reclaim Mel Gorman
2011-07-18 14:56 ` Christoph Lameter
2011-07-18 16:05 ` Mel Gorman
2011-07-18 17:20 ` Christoph Lameter
2011-07-18 21:13 ` Mel Gorman
2011-07-18 21:54 ` Christoph Lameter
2011-07-19 14:01 ` Christoph Lameter
2011-07-20 18:08 ` Christoph Lameter
2011-07-20 19:18 ` Mel Gorman [this message]
2011-07-20 19:28 ` Christoph Lameter
2011-07-20 19:52 ` Christoph Lameter
2011-07-20 21:17 ` Christoph Lameter
2011-07-20 22:48 ` Mel Gorman
2011-07-21 15:24 ` Christoph Lameter
2011-07-15 15:09 ` [PATCH 2/2] mm: page allocator: Reconsider zones for allocation after direct reclaim Mel Gorman
2011-07-19 11:46 ` [PATCH] mm: page allocator: Reconsider zones for allocation after direct reclaim fix Mel Gorman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110720191858.GO5349@suse.de \
--to=mgorman@suse.de \
--cc=akpm@linux-foundation.org \
--cc=cl@linux.com \
--cc=kosaki.motohiro@jp.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=minchan.kim@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).