From: Andrew Morton <akpm@linux-foundation.org>
To: josef@toxicpanda.com
Cc: minchan@kernel.org, linux-mm@kvack.org, hannes@cmpxchg.org,
riel@redhat.com, david@fromorbit.com, kernel-team@fb.com,
Josef Bacik <jbacik@fb.com>
Subject: Re: [PATCH 1/2] mm: use sc->priority for slab shrink targets
Date: Thu, 27 Jul 2017 16:53:48 -0700 [thread overview]
Message-ID: <20170727165348.0e23487a9f98c359fbd5bfea@linux-foundation.org> (raw)
In-Reply-To: <1500576331-31214-2-git-send-email-jbacik@fb.com>
On Thu, 20 Jul 2017 14:45:30 -0400 josef@toxicpanda.com wrote:
> From: Josef Bacik <jbacik@fb.com>
>
> Previously we were using the ratio of the number of lru pages scanned to
> the number of eligible lru pages to determine the number of slab objects
> to scan. The problem with this is that these two things have nothing to
> do with each other,
"nothing"?
> so in slab heavy work loads where there is little to
> no page cache we can end up with the pages scanned being a very low
> number.
In this case the "number of eligible lru pages" will also be low, so
these things do have something to do with each other?
> This means that we reclaim next to no slab pages and waste a
> lot of time reclaiming small amounts of space.
>
> Instead use sc->priority in the same way we use it to determine scan
> amounts for the lru's.
That sounds like a good idea.
Alternatively did you consider hooking into the vmpressure code (or
hannes's new memdelay code) to determine how hard to scan slab?
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next prev parent reply other threads:[~2017-07-28 0:02 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-20 18:45 [PATCH 0/2][V3] slab and general reclaim improvements josef
2017-07-20 18:45 ` [PATCH 1/2] mm: use sc->priority for slab shrink targets josef
2017-07-27 23:53 ` Andrew Morton [this message]
2017-07-28 23:52 ` Josef Bacik
2017-07-20 18:45 ` [PATCH 2/2] mm: make kswapd try harder to keep active pages in cache josef
2017-07-27 23:55 ` [PATCH 0/2][V3] slab and general reclaim improvements Andrew Morton
2017-08-22 19:35 [PATCH 1/2] mm: use sc->priority for slab shrink targets josef
2017-08-24 7:08 ` Minchan Kim
2017-08-24 14:29 ` Andrey Ryabinin
2017-08-24 14:49 ` Josef Bacik
2017-08-24 22:15 ` Dave Chinner
2017-08-24 22:45 ` Josef Bacik
2017-08-25 1:40 ` Dave Chinner
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