From: Andrew Morton <akpm@linux-foundation.org>
To: Andi Kleen <andi@firstfloor.org>
Cc: David Rientjes <rientjes@google.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@suse.cz>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Christoph Lameter <cl@linux-foundation.org>,
Pekka Enberg <penberg@kernel.org>, Tejun Heo <tj@kernel.org>,
Mel Gorman <mgorman@suse.de>, Oleg Nesterov <oleg@redhat.com>,
Rik van Riel <riel@redhat.com>, Jianguo Wu <wujianguo@huawei.com>,
Tim Hockin <thockin@google.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
cgroups@vger.kernel.org, linux-doc@vger.kernel.org
Subject: Re: [patch 03/11] mm, mempolicy: remove per-process flag
Date: Fri, 7 Mar 2014 12:48:31 -0800 [thread overview]
Message-ID: <20140307124831.69b50f829ed34de8651fa461@linux-foundation.org> (raw)
In-Reply-To: <877g866i3c.fsf@tassilo.jf.intel.com>
On Fri, 07 Mar 2014 09:20:39 -0800 Andi Kleen <andi@firstfloor.org> wrote:
> David Rientjes <rientjes@google.com> writes:
> >
> > Per-process flags are a scarce resource so we should free them up
> > whenever possible and make them available. We'll be using it shortly for
> > memcg oom reserves.
>
> I'm not convinced TCP_RR is a meaningfull benchmark for slab.
>
> The shortness seems like an artificial problem.
>
> Just add another flag word to the task_struct? That would seem
> to be the obvious way. People will need it sooner or later anyways.
>
This is basically what the patch does:
@@ -3259,7 +3259,7 @@ __do_cache_alloc(struct kmem_cache *cach
{
void *objp;
- if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) {
+ if (current->mempolicy || unlikely(current->flags & PF_SPREAD_SLAB)) {
objp = alternate_node_alloc(cache, flags);
if (objp)
goto out;
It runs when slab goes into the page allocator for backing store (ie:
relatively rarely). It adds one test-n-branch when a mempolicy is
active and actually removes instructions when no mempolicy is active.
This patch won't be making any difference to anything.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2014-03-07 20:48 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-05 3:58 [patch 00/11] userspace out of memory handling David Rientjes
2014-03-05 3:58 ` [patch 01/11] fork: collapse copy_flags into copy_process David Rientjes
2014-03-05 3:58 ` [patch 02/11] mm, mempolicy: rename slab_node for clarity David Rientjes
2014-03-05 3:59 ` [patch 03/11] mm, mempolicy: remove per-process flag David Rientjes
2014-03-07 17:20 ` Andi Kleen
2014-03-07 20:48 ` Andrew Morton [this message]
2014-03-05 3:59 ` [patch 04/11] mm, memcg: add tunable for oom reserves David Rientjes
2014-03-05 21:17 ` Andrew Morton
2014-03-06 2:53 ` David Rientjes
2014-03-06 21:04 ` Tejun Heo
2014-03-05 3:59 ` [patch 05/11] res_counter: remove interface for locked charging and uncharging David Rientjes
2014-03-05 3:59 ` [patch 06/11] res_counter: add interface for maximum nofail charge David Rientjes
2014-03-05 3:59 ` [patch 07/11] mm, memcg: allow processes handling oom notifications to access reserves David Rientjes
2014-03-06 21:12 ` Tejun Heo
2014-03-05 3:59 ` [patch 08/11] mm, memcg: add memcg oom reserve documentation David Rientjes
2014-03-05 3:59 ` [patch 09/11] mm, page_alloc: allow system oom handlers to use memory reserves David Rientjes
2014-03-06 21:13 ` Tejun Heo
2014-03-05 3:59 ` [patch 10/11] mm, memcg: add memory.oom_control notification for system oom David Rientjes
2014-03-06 21:15 ` Tejun Heo
2014-03-05 3:59 ` [patch 11/11] mm, memcg: allow system oom killer to be disabled David Rientjes
2014-03-06 21:15 ` Tejun Heo
2014-03-05 21:17 ` [patch 00/11] userspace out of memory handling Andrew Morton
2014-03-06 2:52 ` David Rientjes
2014-03-11 12:03 ` Jianguo Wu
2014-03-06 20:49 ` Tejun Heo
2014-03-06 20:55 ` David Rientjes
2014-03-06 20:59 ` Tejun Heo
2014-03-06 21:08 ` David Rientjes
2014-03-06 21:11 ` Tejun Heo
2014-03-06 21:23 ` David Rientjes
2014-03-06 21:29 ` Tejun Heo
2014-03-06 21:33 ` Tejun Heo
2014-03-07 12:23 ` Michal Hocko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20140307124831.69b50f829ed34de8651fa461@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=andi@firstfloor.org \
--cc=cgroups@vger.kernel.org \
--cc=cl@linux-foundation.org \
--cc=hannes@cmpxchg.org \
--cc=kamezawa.hiroyu@jp.fujitsu.com \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@suse.de \
--cc=mhocko@suse.cz \
--cc=oleg@redhat.com \
--cc=penberg@kernel.org \
--cc=riel@redhat.com \
--cc=rientjes@google.com \
--cc=thockin@google.com \
--cc=tj@kernel.org \
--cc=wujianguo@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox