From: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
To: Dave Chinner <david@fromorbit.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
"Nikolay S." <nowhere@hakkenden.ath.cx>,
Michal Hocko <mhocko@suse.cz>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: Kswapd in 3.2.0-rc5 is a CPU hog
Date: Wed, 28 Dec 2011 17:57:38 -0500 [thread overview]
Message-ID: <4EFB9EE2.1050903@gmail.com> (raw)
In-Reply-To: <20111228213359.GF12731@dastard>
(12/28/11 4:33 PM), Dave Chinner wrote:
> On Tue, Dec 27, 2011 at 01:44:05PM +0900, KAMEZAWA Hiroyuki wrote:
>> To me, it seems kswapd does usual work...reclaim small memory until free
>> gets enough. And it seems 'dd' allocates its memory from ZONE_DMA32 because
>> of gfp_t fallbacks.
>>
>>
>> Memo.
>>
>> 1. why shrink_slab() should be called per zone, which is not zone aware.
>> Isn't it enough to call it per priority ?
>
> It is intended that it should be zone aware, but the current
> shrinkers only have global LRUs and hence cannot discriminate
> between objects from different zones easily. And if only a single
> node/zone is being scanned, then we still have to call shirnk_slab()
> to try to free objects in that zone/node, despite it's current
> global scope.
>
> I have some prototype patches that make the major slab caches and
> shrinkers zone/node aware - that is the eventual goal here - but
> first all the major slab cache LRUs need to be converted to be node
> aware first. Then we can pass a nodemask into shrink_slab() and down
> to the shrinkers so that those that have per-node LRUs can scan only
> the appropriate nodes for objects to free. This is someting that I'm
> working on in my spare time, but I have very little of that at the
> moment, unfortunately.
His machine only have one node. per node basis don't help him. We need
1) to make per zone LRU or 2) to implement more clever inter zone
balancing code. but it seems off topic. I'm not sure why you are starting
talk about per node shrinker.
--
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:[~2011-12-28 22:57 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1324437036.4677.5.camel@hakkenden.homenet>
2011-12-21 9:52 ` Kswapd in 3.2.0-rc5 is a CPU hog Michal Hocko
2011-12-21 10:15 ` nowhere
2011-12-21 10:24 ` Michal Hocko
2011-12-21 10:52 ` nowhere
2011-12-21 14:06 ` Alex Elder
2011-12-21 14:19 ` nowhere
2011-12-21 22:55 ` Dave Chinner
2011-12-23 9:01 ` nowhere
2011-12-23 10:20 ` Dave Chinner
2011-12-23 11:04 ` nowhere
2011-12-23 20:45 ` Dave Chinner
2011-12-25 9:09 ` Hillf Danton
2011-12-25 10:21 ` Nikolay S.
2011-12-26 12:35 ` Hillf Danton
2011-12-27 0:20 ` KAMEZAWA Hiroyuki
2011-12-27 13:33 ` Hillf Danton
2011-12-28 0:06 ` KAMEZAWA Hiroyuki
2011-12-27 2:15 ` KAMEZAWA Hiroyuki
2011-12-27 2:50 ` Nikolay S.
2011-12-27 4:44 ` KAMEZAWA Hiroyuki
2011-12-27 6:06 ` nowhere
2011-12-28 21:33 ` Dave Chinner
2011-12-28 22:57 ` KOSAKI Motohiro [this message]
2012-01-02 7:00 ` Dave Chinner
2011-12-27 3:57 ` Minchan Kim
2011-12-27 4:56 ` KAMEZAWA Hiroyuki
2012-01-10 22:33 ` Andrew Morton
2012-01-11 3:25 ` Nikolay S.
2012-01-11 4:42 ` Andrew Morton
2012-01-11 0:33 ` Dave Chinner
2012-01-11 1:17 ` Rik van Riel
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=4EFB9EE2.1050903@gmail.com \
--to=kosaki.motohiro@gmail.com \
--cc=david@fromorbit.com \
--cc=kamezawa.hiroyu@jp.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.cz \
--cc=nowhere@hakkenden.ath.cx \
/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).