From: Minchan Kim <minchan.kim@gmail.com>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ying Han <yinghan@google.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>,
Balbir Singh <balbir@linux.vnet.ibm.com>,
Tejun Heo <tj@kernel.org>, Pavel Emelyanov <xemul@openvz.org>,
Andrew Morton <akpm@linux-foundation.org>,
Li Zefan <lizf@cn.fujitsu.com>, Mel Gorman <mel@csn.ul.ie>,
Christoph Lameter <cl@linux.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Rik van Riel <riel@redhat.com>, Hugh Dickins <hughd@google.com>,
Michal Hocko <mhocko@suse.cz>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Zhu Yanhai <zhu.yanhai@gmail.com>,
linux-mm@kvack.org
Subject: Re: [PATCH 1/3] memcg kswapd thread pool (Was Re: [PATCH V6 00/10] memcg: per cgroup background reclaim
Date: Thu, 21 Apr 2011 17:10:23 +0900 [thread overview]
Message-ID: <BANLkTi=a967ofJGV1_i2vMb9QDGuK7vtog@mail.gmail.com> (raw)
In-Reply-To: <20110421124357.c94a03a5.kamezawa.hiroyu@jp.fujitsu.com>
Hi Kame,
On Thu, Apr 21, 2011 at 12:43 PM, KAMEZAWA Hiroyuki
<kamezawa.hiroyu@jp.fujitsu.com> wrote:
> Ying, please take this just a hint, you don't need to implement this as is.
> ==
> Now, memcg-kswapd is created per a cgroup. Considering there are users
> who creates hundreds on cgroup on a system, it consumes too much
> resources, memory, cputime.
>
> This patch creates a thread pool for memcg-kswapd. All memcg which
> needs background recalim are linked to a list and memcg-kswapd
> picks up a memcg from the list and run reclaim. This reclaimes
> SWAP_CLUSTER_MAX of pages and putback the memcg to the lail of
> list. memcg-kswapd will visit memcgs in round-robin manner and
> reduce usages.
>
I didn't look at code yet but as I just look over the description, I
have a concern.
We have discussed LRU separation between global and memcg.
The clear goal is that how to keep _fairness_.
For example,
memcg-1 : # pages of LRU : 64
memcg-2 : # pages of LRU : 128
memcg-3 : # pages of LRU : 256
If we have to reclaim 96 pages, memcg-1 would be lost half of pages.
It's much greater than others so memcg 1's page LRU rotation cycle
would be very fast, then working set pages in memcg-1 don't have a
chance to promote.
Is it fair?
I think we should consider memcg-LRU size as doing round-robin.
Thanks.
--
Kind regards,
Minchan Kim
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next prev parent reply other threads:[~2011-04-21 8:10 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-19 3:57 [PATCH V6 00/10] memcg: per cgroup background reclaim Ying Han
2011-04-19 3:57 ` [PATCH V6 01/10] Add kswapd descriptor Ying Han
2011-04-19 3:57 ` [PATCH V6 02/10] Add per memcg reclaim watermarks Ying Han
2011-04-19 3:57 ` [PATCH V6 03/10] New APIs to adjust per-memcg wmarks Ying Han
2011-04-19 3:57 ` [PATCH V6 04/10] Infrastructure to support per-memcg reclaim Ying Han
2011-04-19 3:57 ` [PATCH V6 05/10] Implement the select_victim_node within memcg Ying Han
2011-04-19 3:57 ` [PATCH V6 06/10] Per-memcg background reclaim Ying Han
2011-04-20 1:03 ` KAMEZAWA Hiroyuki
2011-04-20 3:25 ` Ying Han
2011-04-20 4:20 ` Ying Han
2012-03-19 8:14 ` Zhu Yanhai
2012-03-20 5:37 ` Ying Han
2011-04-19 3:57 ` [PATCH V6 07/10] Add per-memcg zone "unreclaimable" Ying Han
2011-04-19 3:57 ` [PATCH V6 08/10] Enable per-memcg background reclaim Ying Han
2011-04-19 3:57 ` [PATCH V6 09/10] Add API to export per-memcg kswapd pid Ying Han
2011-04-20 1:15 ` KAMEZAWA Hiroyuki
2011-04-20 3:39 ` Ying Han
2011-04-19 3:57 ` [PATCH V6 10/10] Add some per-memcg stats Ying Han
2011-04-21 2:51 ` [PATCH V6 00/10] memcg: per cgroup background reclaim Johannes Weiner
2011-04-21 3:05 ` Ying Han
2011-04-21 3:53 ` Johannes Weiner
2011-04-21 4:00 ` KAMEZAWA Hiroyuki
2011-04-21 4:24 ` Ying Han
2011-04-21 4:46 ` KAMEZAWA Hiroyuki
2011-04-21 5:08 ` Johannes Weiner
2011-04-21 5:28 ` Ying Han
2011-04-23 1:35 ` Johannes Weiner
2011-04-23 2:10 ` Ying Han
2011-04-23 2:34 ` Johannes Weiner
2011-04-23 3:33 ` Ying Han
2011-04-23 3:41 ` Rik van Riel
2011-04-23 3:49 ` Ying Han
2011-04-27 7:36 ` Johannes Weiner
2011-04-27 17:41 ` Ying Han
2011-04-27 21:37 ` Johannes Weiner
2011-04-21 5:41 ` KAMEZAWA Hiroyuki
2011-04-21 6:23 ` Ying Han
2011-04-23 2:02 ` Johannes Weiner
2011-04-21 3:40 ` KAMEZAWA Hiroyuki
2011-04-21 3:48 ` [PATCH 2/3] weight for memcg background reclaim (Was " KAMEZAWA Hiroyuki
2011-04-21 6:11 ` Ying Han
2011-04-21 6:38 ` KAMEZAWA Hiroyuki
2011-04-21 6:59 ` Ying Han
2011-04-21 7:01 ` KAMEZAWA Hiroyuki
2011-04-21 7:12 ` Ying Han
2011-04-21 3:50 ` [PATCH 3/3/] fix mem_cgroup_watemark_ok " KAMEZAWA Hiroyuki
2011-04-21 5:29 ` Ying Han
2011-04-21 4:22 ` Ying Han
2011-04-21 4:27 ` KAMEZAWA Hiroyuki
2011-04-21 4:31 ` Ying Han
2011-04-21 3:43 ` [PATCH 1/3] memcg kswapd thread pool (Was " KAMEZAWA Hiroyuki
2011-04-21 7:09 ` Ying Han
2011-04-21 7:14 ` KAMEZAWA Hiroyuki
2011-04-21 8:10 ` Minchan Kim [this message]
2011-04-21 8:46 ` KAMEZAWA Hiroyuki
2011-04-21 9:05 ` Minchan Kim
2011-04-21 16:56 ` Ying Han
2011-04-22 1:02 ` Minchan Kim
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