From: Mel Gorman <mgorman@techsingularity.net>
To: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Minchan Kim <minchan@kernel.org>, Michal Hocko <mhocko@suse.cz>,
Vlastimil Babka <vbabka@suse.cz>, Linux-MM <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 0/5] Candidate fixes for premature OOM kills with node-lru v2
Date: Thu, 28 Jul 2016 11:27:51 +0100 [thread overview]
Message-ID: <20160728102751.GB2799@techsingularity.net> (raw)
In-Reply-To: <20160728064432.GA28136@js1304-P5Q-DELUXE>
On Thu, Jul 28, 2016 at 03:44:33PM +0900, Joonsoo Kim wrote:
> > To some extent, it could be "addressed" by immediately reclaiming active
> > pages moving to the inactive list at the cost of distorting page age for a
> > workload that is genuinely close to OOM. That is similar to what zone-lru
> > ended up doing -- fast reclaiming young pages from a zone.
>
> My expectation on my test case is that reclaimers should kick out
> actively used page and make a room for 'fork' because parallel readers
> would work even if reading pages are not cached.
>
> It is sensitive on reclaimers efficiency because parallel readers
> read pages repeatedly and disturb reclaim. I thought that it is a
> good test for node-lru which changes reclaimers efficiency for lower
> zone. However, as you said, this efficiency comes from the cost
> distorting page aging so now I'm not sure if it is a problem that we
> need to consider. Let's skip it?
>
I think we should skip it for now. The alterations are too specific to a
test case that is very close to being genuinely OOM. Adjusting timing
for one OOM case may just lead to complains that OOM is detected too
slowly in others.
> Anyway, thanks for tracking down the problem.
>
My pleasure, thanks to both you and Minchan for persisting with this as
we got some important fixes out of the discussion.
--
Mel Gorman
SUSE Labs
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prev parent reply other threads:[~2016-07-28 10:27 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-21 14:10 [PATCH 0/5] Candidate fixes for premature OOM kills with node-lru v2 Mel Gorman
2016-07-21 14:10 ` [PATCH 1/5] mm: add per-zone lru list stat Mel Gorman
2016-07-22 15:51 ` Johannes Weiner
2016-07-21 14:10 ` [PATCH 2/5] mm, vmscan: Remove highmem_file_pages Mel Gorman
2016-07-22 15:53 ` Johannes Weiner
2016-07-25 8:09 ` Minchan Kim
2016-07-25 9:23 ` [PATCH] mm, vmscan: remove highmem_file_pages -fix Mel Gorman
2016-07-21 14:10 ` [PATCH 3/5] mm: Remove reclaim and compaction retry approximations Mel Gorman
2016-07-22 15:57 ` Johannes Weiner
2016-07-25 8:18 ` Minchan Kim
2016-07-21 14:11 ` [PATCH 4/5] mm: consider per-zone inactive ratio to deactivate Mel Gorman
2016-07-21 15:52 ` Johannes Weiner
2016-07-21 14:11 ` [PATCH 5/5] mm, vmscan: Account for skipped pages as a partial scan Mel Gorman
2016-07-22 16:02 ` Johannes Weiner
2016-07-25 8:39 ` Minchan Kim
2016-07-25 9:52 ` Mel Gorman
2016-07-26 8:16 ` Joonsoo Kim
2016-07-26 8:26 ` Joonsoo Kim
2016-07-26 8:11 ` [PATCH 0/5] Candidate fixes for premature OOM kills with node-lru v2 Joonsoo Kim
2016-07-26 12:50 ` Mel Gorman
2016-07-28 6:44 ` Joonsoo Kim
2016-07-28 10:27 ` Mel Gorman [this message]
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