From: Christoph Lameter <cl@gentwo.org>
To: Vladimir Davydov <vdavydov@parallels.com>
Cc: akpm@linux-foundation.org, hannes@cmpxchg.org, mhocko@suse.cz,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [PATCH -mm 4/8] slub: never fail kmem_cache_shrink
Date: Fri, 30 May 2014 09:46:33 -0500 (CDT) [thread overview]
Message-ID: <alpine.DEB.2.10.1405300937560.11943@gentwo.org> (raw)
In-Reply-To: <ac8907cace921c3209aa821649349106f4f70b34.1401457502.git.vdavydov@parallels.com>
On Fri, 30 May 2014, Vladimir Davydov wrote:
> SLUB's kmem_cache_shrink not only removes empty slabs from the cache,
> but also sorts slabs by the number of objects in-use to cope with
> fragmentation. To achieve that, it tries to allocate a temporary array.
> If it fails, it will abort the whole procedure.
If we cannot allocate a kernel structure that is mostly less than a page
size then we have much more important things to worry about.
The maximum number of objects per slab is 512 on my system here.
> This is unacceptable for kmemcg, where we want to be sure that all empty
> slabs are removed from the cache on memcg offline, so let's just skip
> the de-fragmentation step if the allocation fails, but still get rid of
> empty slabs.
Lets just try the shrink and log the fact that it failed? Try again later?
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next prev parent reply other threads:[~2014-05-30 14:46 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-30 13:51 [PATCH -mm 0/8] memcg/slab: reintroduce dead cache self-destruction Vladimir Davydov
2014-05-30 13:51 ` [PATCH -mm 1/8] memcg: cleanup memcg_cache_params refcnt usage Vladimir Davydov
2014-05-30 14:31 ` Christoph Lameter
2014-05-30 13:51 ` [PATCH -mm 2/8] memcg: destroy kmem caches when last slab is freed Vladimir Davydov
2014-05-30 14:32 ` Christoph Lameter
2014-05-30 13:51 ` [PATCH -mm 3/8] memcg: mark caches that belong to offline memcgs as dead Vladimir Davydov
2014-05-30 14:33 ` Christoph Lameter
2014-05-30 13:51 ` [PATCH -mm 4/8] slub: never fail kmem_cache_shrink Vladimir Davydov
2014-05-30 14:46 ` Christoph Lameter [this message]
2014-05-31 10:18 ` Vladimir Davydov
2014-06-02 15:13 ` Christoph Lameter
2014-05-30 13:51 ` [PATCH -mm 5/8] slab: remove kmem_cache_shrink retval Vladimir Davydov
2014-05-30 14:49 ` Christoph Lameter
2014-05-31 10:27 ` Vladimir Davydov
2014-06-02 15:16 ` Christoph Lameter
2014-06-03 9:06 ` Vladimir Davydov
2014-06-03 14:48 ` Christoph Lameter
2014-06-03 19:00 ` Vladimir Davydov
2014-05-30 13:51 ` [PATCH -mm 6/8] slub: do not use cmpxchg for adding cpu partials when irqs disabled Vladimir Davydov
2014-05-30 13:51 ` [PATCH -mm 7/8] slub: make dead caches discard free slabs immediately Vladimir Davydov
2014-05-30 14:57 ` Christoph Lameter
2014-05-31 11:04 ` Vladimir Davydov
2014-06-02 4:24 ` Joonsoo Kim
2014-06-02 11:47 ` Vladimir Davydov
2014-06-02 14:03 ` Joonsoo Kim
2014-06-02 15:17 ` Christoph Lameter
2014-06-03 8:16 ` Vladimir Davydov
2014-06-04 8:53 ` Joonsoo Kim
2014-06-04 9:47 ` Vladimir Davydov
2014-05-30 13:51 ` [PATCH -mm 8/8] slab: reap dead memcg caches aggressively Vladimir Davydov
2014-05-30 15:01 ` Christoph Lameter
2014-05-31 11:19 ` Vladimir Davydov
2014-06-02 15:24 ` Christoph Lameter
2014-06-03 20:18 ` Vladimir Davydov
2014-06-02 4:41 ` Joonsoo Kim
2014-06-02 12:10 ` Vladimir Davydov
2014-06-02 14:01 ` Joonsoo Kim
2014-06-03 8:21 ` Vladimir Davydov
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