From: Andrew Morton <akpm@linux-foundation.org>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>,
Chris Wilson <chris@chris-wilson.co.uk>,
linux-mm@kvack.org, intel-gfx@lists.freedesktop.org,
Michal Hocko <mhocko@suse.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Hillf Danton <hillf.zj@alibaba-inc.com>,
Mel Gorman <mgorman@techsingularity.net>,
Shaohua Li <shli@fb.com>
Subject: Re: [PATCH 1/2] mm: Track actual nr_scanned during shrink_slab()
Date: Fri, 25 Aug 2017 14:41:56 -0700 [thread overview]
Message-ID: <20170825144156.f70bfad8dd982d1a320e41ca@linux-foundation.org> (raw)
In-Reply-To: <29aae2cd-85a8-f3c4-66e2-4d4f5a2732c1@suse.cz>
On Thu, 24 Aug 2017 10:00:49 +0200 Vlastimil Babka <vbabka@suse.cz> wrote:
> > Even if a
> > shrinker has a mistake, VM will have big trouble like infinite loop.
>
> We could fake 0 as 1 or something, at least.
If the shrinker returns sc->nr_scanned==0 then that's a buggy shrinker
- it should return SHRINK_STOP in that case. Only a single shrinker
(i915) presently uses sc->nr_scanned and that one gets it right. I
think it's OK - there's a limit to how far we should go defending
against buggy kernel code, surely.
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next prev parent reply other threads:[~2017-08-25 21:42 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-12 11:34 [PATCH] mm: Reward slab shrinkers that reclaim more than they were asked Chris Wilson
2017-08-15 22:30 ` Andrew Morton
2017-08-15 22:53 ` Chris Wilson
2017-08-22 13:53 ` [PATCH 1/2] mm: Track actual nr_scanned during shrink_slab() Chris Wilson
2017-08-22 13:53 ` [PATCH 2/2] drm/i915: Wire up shrinkctl->nr_scanned Chris Wilson
2017-08-22 22:45 ` Andrew Morton
2017-08-23 14:20 ` Chris Wilson
2017-08-24 5:11 ` [PATCH 1/2] mm: Track actual nr_scanned during shrink_slab() Minchan Kim
2017-08-24 8:00 ` Vlastimil Babka
2017-08-25 21:41 ` Andrew Morton [this message]
2017-08-28 8:09 ` Minchan Kim
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