From: Johannes Weiner <hannes@cmpxchg.org>
To: Mel Gorman <mgorman@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Jiri Slaby <jslaby@suse.cz>,
Valdis Kletnieks <Valdis.Kletnieks@vt.edu>,
Rik van Riel <riel@redhat.com>,
Zlatko Calusic <zcalusic@bitsync.net>,
dormando <dormando@rydia.net>, Michal Hocko <mhocko@suse.cz>,
Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 08/10] mm: vmscan: Have kswapd shrink slab only once per priority
Date: Thu, 18 Apr 2013 09:43:06 -0700 [thread overview]
Message-ID: <20130418164306.GJ2018@cmpxchg.org> (raw)
In-Reply-To: <1365710278-6807-9-git-send-email-mgorman@suse.de>
On Thu, Apr 11, 2013 at 08:57:56PM +0100, Mel Gorman wrote:
> If kswaps fails to make progress but continues to shrink slab then it'll
> either discard all of slab or consume CPU uselessly scanning shrinkers.
> This patch causes kswapd to only call the shrinkers once per priority.
But the priority level changes _only_ when kswapd is not making
progress, so I don't see how this fixes this case.
On the other hand, what about shrinkable memory like dentries and
inodes that build up during a streaming IO load like a backup program?
Kswapd may be cooperating with the page allocator and never change
priority as it reclaims the continuous file page stream, but it won't
do the same for the stream of slab memory.
So if anything, I would expect us to lay off slab memory when lru
reclaim is struggling, but receive continuous aging and pushback as
long as lru reclaim is comfortably running alongside the workload.
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next prev parent reply other threads:[~2013-04-18 16:44 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-11 19:57 [PATCH 0/10] Reduce system disruption due to kswapd V3 Mel Gorman
2013-04-11 19:57 ` [PATCH 01/10] mm: vmscan: Limit the number of pages kswapd reclaims at each priority Mel Gorman
2013-04-11 19:57 ` [PATCH 02/10] mm: vmscan: Obey proportional scanning requirements for kswapd Mel Gorman
2013-04-18 15:01 ` Johannes Weiner
2013-04-18 15:58 ` Mel Gorman
2013-04-11 19:57 ` [PATCH 03/10] mm: vmscan: Flatten kswapd priority loop Mel Gorman
2013-04-18 15:02 ` Johannes Weiner
2013-04-11 19:57 ` [PATCH 04/10] mm: vmscan: Decide whether to compact the pgdat based on reclaim progress Mel Gorman
2013-04-18 15:09 ` Johannes Weiner
2013-04-11 19:57 ` [PATCH 05/10] mm: vmscan: Do not allow kswapd to scan at maximum priority Mel Gorman
2013-04-18 15:11 ` Johannes Weiner
2013-04-11 19:57 ` [PATCH 06/10] mm: vmscan: Have kswapd writeback pages based on dirty pages encountered, not priority Mel Gorman
2013-04-18 15:16 ` Johannes Weiner
2013-04-11 19:57 ` [PATCH 07/10] mm: vmscan: Block kswapd if it is encountering pages under writeback Mel Gorman
2013-04-11 19:57 ` [PATCH 08/10] mm: vmscan: Have kswapd shrink slab only once per priority Mel Gorman
2013-04-18 16:43 ` Johannes Weiner [this message]
2013-04-11 19:57 ` [PATCH 09/10] mm: vmscan: Check if kswapd should writepage once per pgdat scan Mel Gorman
2013-04-18 16:44 ` Johannes Weiner
2013-04-11 19:57 ` [PATCH 10/10] mm: vmscan: Move logic from balance_pgdat() to kswapd_shrink_zone() Mel Gorman
2013-04-18 16:56 ` Johannes Weiner
-- strict thread matches above, loose matches on Subject: below --
2013-04-09 11:06 [PATCH 0/10] Reduce system disruption due to kswapd V2 Mel Gorman
2013-04-09 11:07 ` [PATCH 08/10] mm: vmscan: Have kswapd shrink slab only once per priority Mel Gorman
2013-03-17 13:04 [RFC PATCH 0/8] Reduce system disruption due to kswapd Mel Gorman
2013-03-17 13:04 ` [PATCH 08/10] mm: vmscan: Have kswapd shrink slab only once per priority Mel Gorman
2013-03-17 14:53 ` Andi Kleen
2013-03-21 16:47 ` Michal Hocko
2013-03-21 19:47 ` Rik van Riel
2013-04-09 6:53 ` Joonsoo Kim
2013-04-09 8:41 ` Simon Jeons
2013-04-09 11:13 ` Mel Gorman
2013-04-10 1:07 ` Dave Chinner
2013-04-10 5:23 ` Joonsoo Kim
2013-04-11 9:53 ` Mel Gorman
2013-04-10 5:21 ` Joonsoo Kim
2013-04-11 10:01 ` Mel Gorman
2013-04-11 10:29 ` Ric Mason
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