From: Christoph Lameter <cl@linux.com>
To: David Rientjes <rientjes@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.cz>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Mel Gorman <mgorman@suse.de>, Rik van Riel <riel@redhat.com>,
Pekka Enberg <penberg@kernel.org>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
cgroups@vger.kernel.org
Subject: Re: [patch 3/8] mm, mempolicy: remove per-process flag
Date: Wed, 4 Dec 2013 15:24:52 +0000 [thread overview]
Message-ID: <00000142be3633ba-2a459537-58fb-444b-a99f-33ff5e5b2aed-000000@email.amazonses.com> (raw)
In-Reply-To: <alpine.DEB.2.02.1312032117490.29733@chino.kir.corp.google.com>
On Tue, 3 Dec 2013, David Rientjes wrote:
> PF_MEMPOLICY is an unnecessary optimization for CONFIG_SLAB users.
> There's no significant performance degradation to checking
> current->mempolicy rather than current->flags & PF_MEMPOLICY in the
> allocation path, especially since this is considered unlikely().
The use of current->mempolicy increase the cache footprint since its in a
rarely used cacheline. This performance issue would occur when memory
policies are not used since that cacheline would then have to be touched
regardless of memory policies be in effect or not. PF_MEMPOLICY was used
to avoid touching the cacheline.
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next prev parent reply other threads:[~2013-12-04 15:24 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-19 13:14 user defined OOM policies Michal Hocko
2013-11-19 13:40 ` Michal Hocko
2013-11-20 8:02 ` David Rientjes
2013-11-20 15:22 ` Michal Hocko
2013-11-20 17:14 ` Luigi Semenzato
2013-11-21 3:36 ` David Rientjes
2013-11-21 7:03 ` Luigi Semenzato
2013-11-22 18:08 ` Johannes Weiner
2013-11-28 11:36 ` Michal Hocko
2013-11-26 1:29 ` David Rientjes
2013-11-28 11:42 ` Michal Hocko
2013-12-02 23:09 ` David Rientjes
2013-11-21 3:33 ` David Rientjes
2013-11-28 11:54 ` Michal Hocko
2013-12-02 23:07 ` David Rientjes
2013-12-04 5:19 ` [patch 1/8] fork: collapse copy_flags into copy_process David Rientjes
2013-12-04 5:19 ` [patch 2/8] mm, mempolicy: rename slab_node for clarity David Rientjes
2013-12-04 15:21 ` Christoph Lameter
2013-12-04 5:20 ` [patch 3/8] mm, mempolicy: remove per-process flag David Rientjes
2013-12-04 15:24 ` Christoph Lameter [this message]
2013-12-05 0:53 ` David Rientjes
2013-12-05 19:05 ` Christoph Lameter
2013-12-05 23:53 ` David Rientjes
2013-12-06 14:46 ` Christoph Lameter
2013-12-04 5:20 ` [patch 4/8] mm, memcg: add tunable for oom reserves David Rientjes
2013-12-04 5:20 ` [patch 5/8] res_counter: remove interface for locked charging and uncharging David Rientjes
2013-12-04 5:20 ` [patch 6/8] res_counter: add interface for maximum nofail charge David Rientjes
2013-12-04 5:20 ` [patch 7/8] mm, memcg: allow processes handling oom notifications to access reserves David Rientjes
2013-12-04 5:45 ` Johannes Weiner
2013-12-05 1:49 ` David Rientjes
2013-12-05 2:50 ` Tejun Heo
2013-12-05 23:49 ` David Rientjes
2013-12-06 17:34 ` Johannes Weiner
2013-12-07 16:38 ` Tim Hockin
2013-12-07 17:40 ` Johannes Weiner
2013-12-07 18:12 ` Tim Hockin
2013-12-07 19:06 ` Johannes Weiner
2013-12-07 21:04 ` Tim Hockin
2013-12-06 19:01 ` Tejun Heo
2013-12-09 20:10 ` David Rientjes
2013-12-09 22:37 ` Johannes Weiner
2013-12-10 21:50 ` Tejun Heo
2013-12-10 23:55 ` David Rientjes
2013-12-11 9:49 ` Mel Gorman
2013-12-11 12:42 ` Tejun Heo
2013-12-12 5:37 ` Tim Hockin
2013-12-12 14:21 ` Tejun Heo
2013-12-12 16:32 ` Michal Hocko
2013-12-12 16:37 ` Tejun Heo
2013-12-12 18:42 ` Tim Hockin
2013-12-12 19:23 ` Tejun Heo
2013-12-13 0:23 ` Tim Hockin
2013-12-13 11:47 ` Tejun Heo
2013-12-04 5:20 ` [patch 8/8] mm, memcg: add memcg oom reserve documentation David Rientjes
2013-11-20 17:25 ` user defined OOM policies Vladimir Murzin
2013-11-20 17:21 ` Vladimir Murzin
2013-11-20 17:33 ` Michal Hocko
2013-11-21 3:38 ` David Rientjes
2013-11-21 17:13 ` Michal Hocko
2013-11-26 1:36 ` David Rientjes
2013-11-22 7:28 ` Vladimir Murzin
2013-11-22 13:18 ` Michal Hocko
2013-11-20 7:50 ` David Rientjes
2013-11-22 0:19 ` Jörn Engel
2013-11-26 1:31 ` David Rientjes
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