From: Mel Gorman <mgorman@suse.de>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Rik van Riel <riel@redhat.com>, Michal Hocko <mhocko@suse.cz>,
Hugh Dickins <hughd@google.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [patch 7/8] mm: vmscan: compaction works against zones, not lruvecs
Date: Thu, 13 Dec 2012 11:12:54 +0000 [thread overview]
Message-ID: <20121213111254.GB1009@suse.de> (raw)
In-Reply-To: <1355348620-9382-8-git-send-email-hannes@cmpxchg.org>
On Wed, Dec 12, 2012 at 04:43:39PM -0500, Johannes Weiner wrote:
> The restart logic for when reclaim operates back to back with
> compaction is currently applied on the lruvec level. But this does
> not make sense, because the container of interest for compaction is a
> zone as a whole, not the zone pages that are part of a certain memory
> cgroup.
>
> Negative impact is bounded. For one, the code checks that the lruvec
> has enough reclaim candidates, so it does not risk getting stuck on a
> condition that can not be fulfilled. And the unfairness of hammering
> on one particular memory cgroup to make progress in a zone will be
> amortized by the round robin manner in which reclaim goes through the
> memory cgroups. Still, this can lead to unnecessary allocation
> latencies when the code elects to restart on a hard to reclaim or
> small group when there are other, more reclaimable groups in the zone.
>
> Move this logic to the zone level and restart reclaim for all memory
> cgroups in a zone when compaction requires more free pages from it.
>
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mgorman@suse.de>
--
Mel Gorman
SUSE Labs
WARNING: multiple messages have this Message-ID (diff)
From: Mel Gorman <mgorman@suse.de>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Rik van Riel <riel@redhat.com>, Michal Hocko <mhocko@suse.cz>,
Hugh Dickins <hughd@google.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [patch 7/8] mm: vmscan: compaction works against zones, not lruvecs
Date: Thu, 13 Dec 2012 11:12:54 +0000 [thread overview]
Message-ID: <20121213111254.GB1009@suse.de> (raw)
In-Reply-To: <1355348620-9382-8-git-send-email-hannes@cmpxchg.org>
On Wed, Dec 12, 2012 at 04:43:39PM -0500, Johannes Weiner wrote:
> The restart logic for when reclaim operates back to back with
> compaction is currently applied on the lruvec level. But this does
> not make sense, because the container of interest for compaction is a
> zone as a whole, not the zone pages that are part of a certain memory
> cgroup.
>
> Negative impact is bounded. For one, the code checks that the lruvec
> has enough reclaim candidates, so it does not risk getting stuck on a
> condition that can not be fulfilled. And the unfairness of hammering
> on one particular memory cgroup to make progress in a zone will be
> amortized by the round robin manner in which reclaim goes through the
> memory cgroups. Still, this can lead to unnecessary allocation
> latencies when the code elects to restart on a hard to reclaim or
> small group when there are other, more reclaimable groups in the zone.
>
> Move this logic to the zone level and restart reclaim for all memory
> cgroups in a zone when compaction requires more free pages from it.
>
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mgorman@suse.de>
--
Mel Gorman
SUSE Labs
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next prev parent reply other threads:[~2012-12-13 11:12 UTC|newest]
Thread overview: 114+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-12 21:43 [patch 0/8] page reclaim bits Johannes Weiner
2012-12-12 21:43 ` Johannes Weiner
2012-12-12 21:43 ` [patch 1/8] mm: memcg: only evict file pages when we have plenty Johannes Weiner
2012-12-12 21:43 ` Johannes Weiner
2012-12-12 21:53 ` Rik van Riel
2012-12-12 21:53 ` Rik van Riel
2012-12-12 22:28 ` Johannes Weiner
2012-12-12 22:28 ` Johannes Weiner
2012-12-13 10:07 ` Mel Gorman
2012-12-13 10:07 ` Mel Gorman
2012-12-13 14:44 ` Mel Gorman
2012-12-13 14:44 ` Mel Gorman
2012-12-13 14:55 ` Michal Hocko
2012-12-13 14:55 ` Michal Hocko
2012-12-16 1:21 ` Simon Jeons
2012-12-16 1:21 ` Simon Jeons
2012-12-17 15:54 ` Michal Hocko
2012-12-17 15:54 ` Michal Hocko
2012-12-19 5:21 ` Simon Jeons
2012-12-19 5:21 ` Simon Jeons
2012-12-19 9:20 ` Mel Gorman
2012-12-19 9:20 ` Mel Gorman
2012-12-13 5:36 ` Simon Jeons
2012-12-13 5:36 ` Simon Jeons
2012-12-13 5:34 ` Simon Jeons
2012-12-13 5:34 ` Simon Jeons
2012-12-12 21:43 ` [patch 2/8] mm: vmscan: disregard swappiness shortly before going OOM Johannes Weiner
2012-12-12 21:43 ` Johannes Weiner
2012-12-12 22:01 ` Rik van Riel
2012-12-12 22:01 ` Rik van Riel
2012-12-13 5:56 ` Simon Jeons
2012-12-13 5:56 ` Simon Jeons
2012-12-13 10:34 ` Mel Gorman
2012-12-13 10:34 ` Mel Gorman
2012-12-13 15:29 ` Michal Hocko
2012-12-13 15:29 ` Michal Hocko
2012-12-13 16:05 ` Michal Hocko
2012-12-13 16:05 ` Michal Hocko
2012-12-13 22:25 ` Satoru Moriya
2012-12-13 22:25 ` Satoru Moriya
2012-12-14 4:50 ` Johannes Weiner
2012-12-14 4:50 ` Johannes Weiner
2012-12-14 8:37 ` Michal Hocko
2012-12-14 8:37 ` Michal Hocko
2012-12-14 15:43 ` Rik van Riel
2012-12-14 15:43 ` Rik van Riel
2012-12-14 16:13 ` Michal Hocko
2012-12-14 16:13 ` Michal Hocko
2012-12-15 0:18 ` Johannes Weiner
2012-12-15 0:18 ` Johannes Weiner
2012-12-17 16:37 ` Michal Hocko
2012-12-17 16:37 ` Michal Hocko
2012-12-17 17:54 ` Johannes Weiner
2012-12-17 17:54 ` Johannes Weiner
2012-12-17 19:58 ` Michal Hocko
2012-12-17 19:58 ` Michal Hocko
2012-12-14 20:17 ` Satoru Moriya
2012-12-14 20:17 ` Satoru Moriya
2012-12-14 19:44 ` Satoru Moriya
2012-12-14 19:44 ` Satoru Moriya
2012-12-13 19:05 ` Johannes Weiner
2012-12-13 19:05 ` Johannes Weiner
2012-12-13 19:47 ` Mel Gorman
2012-12-13 19:47 ` Mel Gorman
2012-12-12 21:43 ` [patch 3/8] mm: vmscan: save work scanning (almost) empty LRU lists Johannes Weiner
2012-12-12 21:43 ` Johannes Weiner
2012-12-12 22:02 ` Rik van Riel
2012-12-12 22:02 ` Rik van Riel
2012-12-13 10:41 ` Mel Gorman
2012-12-13 10:41 ` Mel Gorman
2012-12-13 19:33 ` Johannes Weiner
2012-12-13 19:33 ` Johannes Weiner
2012-12-13 15:43 ` Michal Hocko
2012-12-13 15:43 ` Michal Hocko
2012-12-13 19:38 ` Johannes Weiner
2012-12-13 19:38 ` Johannes Weiner
2012-12-14 8:46 ` Michal Hocko
2012-12-14 8:46 ` Michal Hocko
2012-12-12 21:43 ` [patch 4/8] mm: vmscan: clarify LRU balancing close to OOM Johannes Weiner
2012-12-12 21:43 ` Johannes Weiner
2012-12-12 22:03 ` Rik van Riel
2012-12-12 22:03 ` Rik van Riel
2012-12-13 10:46 ` Mel Gorman
2012-12-13 10:46 ` Mel Gorman
2012-12-12 21:43 ` [patch 5/8] mm: vmscan: improve comment on low-page cache handling Johannes Weiner
2012-12-12 21:43 ` Johannes Weiner
2012-12-12 22:04 ` Rik van Riel
2012-12-12 22:04 ` Rik van Riel
2012-12-13 10:47 ` Mel Gorman
2012-12-13 10:47 ` Mel Gorman
2012-12-13 16:07 ` Michal Hocko
2012-12-13 16:07 ` Michal Hocko
2012-12-12 21:43 ` [patch 6/8] mm: vmscan: clean up get_scan_count() Johannes Weiner
2012-12-12 21:43 ` Johannes Weiner
2012-12-12 22:06 ` Rik van Riel
2012-12-12 22:06 ` Rik van Riel
2012-12-13 11:07 ` Mel Gorman
2012-12-13 11:07 ` Mel Gorman
2012-12-13 16:18 ` Michal Hocko
2012-12-13 16:18 ` Michal Hocko
2012-12-12 21:43 ` [patch 7/8] mm: vmscan: compaction works against zones, not lruvecs Johannes Weiner
2012-12-12 21:43 ` Johannes Weiner
2012-12-12 22:31 ` Rik van Riel
2012-12-12 22:31 ` Rik van Riel
2012-12-13 11:12 ` Mel Gorman [this message]
2012-12-13 11:12 ` Mel Gorman
2012-12-13 16:48 ` Michal Hocko
2012-12-13 16:48 ` Michal Hocko
2012-12-12 21:43 ` [patch 8/8] mm: reduce rmap overhead for ex-KSM page copies created on swap faults Johannes Weiner
2012-12-12 21:43 ` Johannes Weiner
2012-12-12 22:34 ` Rik van Riel
2012-12-12 22:34 ` Rik van Riel
2012-12-12 21:50 ` [patch 0/8] page reclaim bits Andrew Morton
2012-12-12 21:50 ` Andrew Morton
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