From: Tejun Heo <tj@kernel.org>
To: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>,
Glauber Costa <glommer@parallels.com>,
linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
kamezawa.hiroyu@jp.fujitsu.com, devel@openvz.org,
linux-mm@kvack.org, Suleiman Souhlal <suleiman@google.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
David Rientjes <rientjes@google.com>,
Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [PATCH v3 04/13] kmem accounting basic infrastructure
Date: Thu, 27 Sep 2012 07:58:02 -0700 [thread overview]
Message-ID: <20120927145802.GC4251@mtj.dyndns.org> (raw)
In-Reply-To: <20120927144307.GH3429@suse.de>
Hello, Mel.
On Thu, Sep 27, 2012 at 03:43:07PM +0100, Mel Gorman wrote:
> > I'm not too convinced. First of all, the overhead added by kmemcg
> > isn't big.
>
> Really?
>
> If kmemcg was globally accounted then every __GFP_KMEMCG allocation in
> the page allocator potentially ends up down in
> __memcg_kmem_newpage_charge which
>
> 1. takes RCU read lock
> 2. looks up cgroup from task
> 3. takes a reference count
> 4. memcg_charge_kmem -> __mem_cgroup_try_charge
> 5. release reference count
>
> That's a *LOT* of work to incur for cgroups that do not care about kernel
> accounting. This is why I thought it was reasonable that the kmem accounting
> not be global.
But that happens only when pages enter and leave slab and if it still
is significant, we can try to further optimize charging. Given that
this is only for cases where memcg is already in use and we provide a
switch to disable it globally, I really don't think this warrants
implementing fully hierarchy configuration.
Thanks.
--
tejun
WARNING: multiple messages have this Message-ID (diff)
From: Tejun Heo <tj@kernel.org>
To: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>,
Glauber Costa <glommer@parallels.com>,
linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
kamezawa.hiroyu@jp.fujitsu.com, devel@openvz.org,
linux-mm@kvack.org, Suleiman Souhlal <suleiman@google.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
David Rientjes <rientjes@google.com>,
Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [PATCH v3 04/13] kmem accounting basic infrastructure
Date: Thu, 27 Sep 2012 07:58:02 -0700 [thread overview]
Message-ID: <20120927145802.GC4251@mtj.dyndns.org> (raw)
In-Reply-To: <20120927144307.GH3429@suse.de>
Hello, Mel.
On Thu, Sep 27, 2012 at 03:43:07PM +0100, Mel Gorman wrote:
> > I'm not too convinced. First of all, the overhead added by kmemcg
> > isn't big.
>
> Really?
>
> If kmemcg was globally accounted then every __GFP_KMEMCG allocation in
> the page allocator potentially ends up down in
> __memcg_kmem_newpage_charge which
>
> 1. takes RCU read lock
> 2. looks up cgroup from task
> 3. takes a reference count
> 4. memcg_charge_kmem -> __mem_cgroup_try_charge
> 5. release reference count
>
> That's a *LOT* of work to incur for cgroups that do not care about kernel
> accounting. This is why I thought it was reasonable that the kmem accounting
> not be global.
But that happens only when pages enter and leave slab and if it still
is significant, we can try to further optimize charging. Given that
this is only for cases where memcg is already in use and we provide a
switch to disable it globally, I really don't think this warrants
implementing fully hierarchy configuration.
Thanks.
--
tejun
--
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:[~2012-09-27 14:58 UTC|newest]
Thread overview: 323+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-18 14:03 [PATCH v3 00/13] kmem controller for memcg Glauber Costa
2012-09-18 14:03 ` Glauber Costa
2012-09-18 14:03 ` Glauber Costa
2012-09-18 14:03 ` [PATCH v3 01/13] memcg: Make it possible to use the stock for more than one page Glauber Costa
2012-09-18 14:03 ` Glauber Costa
2012-09-18 14:03 ` Glauber Costa
2012-10-01 18:48 ` Johannes Weiner
2012-10-01 18:48 ` Johannes Weiner
2012-09-18 14:03 ` [PATCH v3 02/13] memcg: Reclaim when more than one page needed Glauber Costa
2012-09-18 14:03 ` Glauber Costa
2012-09-18 14:03 ` Glauber Costa
2012-10-01 19:00 ` Johannes Weiner
2012-10-01 19:00 ` Johannes Weiner
2012-09-18 14:04 ` [PATCH v3 03/13] memcg: change defines to an enum Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-10-01 19:06 ` Johannes Weiner
2012-10-01 19:06 ` Johannes Weiner
2012-10-01 19:06 ` Johannes Weiner
2012-10-02 9:10 ` Glauber Costa
2012-10-02 9:10 ` Glauber Costa
2012-09-18 14:04 ` [PATCH v3 04/13] kmem accounting basic infrastructure Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-21 16:34 ` Tejun Heo
2012-09-21 16:34 ` Tejun Heo
2012-09-24 8:09 ` Glauber Costa
2012-09-24 8:09 ` Glauber Costa
2012-09-24 8:09 ` Glauber Costa
2012-09-26 14:03 ` Michal Hocko
2012-09-26 14:03 ` Michal Hocko
2012-09-26 14:03 ` Michal Hocko
2012-09-26 14:33 ` Glauber Costa
2012-09-26 14:33 ` Glauber Costa
2012-09-26 16:01 ` Michal Hocko
2012-09-26 16:01 ` Michal Hocko
2012-09-26 16:01 ` Michal Hocko
2012-09-26 17:34 ` Glauber Costa
2012-09-26 17:34 ` Glauber Costa
2012-09-26 16:36 ` Tejun Heo
2012-09-26 16:36 ` Tejun Heo
2012-09-26 16:36 ` Tejun Heo
2012-09-26 17:36 ` Glauber Costa
2012-09-26 17:36 ` Glauber Costa
2012-09-26 17:44 ` Tejun Heo
2012-09-26 17:44 ` Tejun Heo
2012-09-26 17:44 ` Tejun Heo
2012-09-26 17:53 ` Glauber Costa
2012-09-26 17:53 ` Glauber Costa
2012-09-26 18:01 ` Tejun Heo
2012-09-26 18:01 ` Tejun Heo
2012-09-26 18:56 ` Glauber Costa
2012-09-26 18:56 ` Glauber Costa
2012-09-26 18:56 ` Glauber Costa
2012-09-26 19:34 ` Tejun Heo
2012-09-26 19:34 ` Tejun Heo
2012-09-26 19:34 ` Tejun Heo
2012-09-26 19:46 ` Glauber Costa
2012-09-26 19:46 ` Glauber Costa
2012-09-26 19:56 ` Tejun Heo
2012-09-26 19:56 ` Tejun Heo
2012-09-26 19:56 ` Tejun Heo
2012-09-26 20:02 ` Glauber Costa
2012-09-26 20:02 ` Glauber Costa
2012-09-26 20:16 ` Tejun Heo
2012-09-26 20:16 ` Tejun Heo
2012-09-26 20:16 ` Tejun Heo
2012-09-26 21:24 ` Glauber Costa
2012-09-26 21:24 ` Glauber Costa
2012-09-26 22:10 ` Tejun Heo
2012-09-26 22:10 ` Tejun Heo
2012-09-26 22:10 ` Tejun Heo
2012-09-26 22:29 ` Glauber Costa
2012-09-26 22:29 ` Glauber Costa
2012-09-26 22:42 ` Tejun Heo
2012-09-26 22:42 ` Tejun Heo
2012-09-26 22:42 ` Tejun Heo
2012-09-26 22:54 ` Glauber Costa
2012-09-26 22:54 ` Glauber Costa
2012-09-26 23:08 ` Tejun Heo
2012-09-26 23:08 ` Tejun Heo
2012-09-26 23:08 ` Tejun Heo
2012-09-26 23:20 ` Glauber Costa
2012-09-26 23:20 ` Glauber Costa
2012-09-26 23:33 ` Tejun Heo
2012-09-26 23:33 ` Tejun Heo
2012-09-27 12:15 ` Michal Hocko
2012-09-27 12:15 ` Michal Hocko
2012-09-27 12:15 ` Michal Hocko
2012-09-27 12:20 ` Glauber Costa
2012-09-27 12:20 ` Glauber Costa
2012-09-27 12:40 ` Michal Hocko
2012-09-27 12:40 ` Michal Hocko
2012-09-27 12:40 ` Michal Hocko
2012-09-27 12:40 ` Glauber Costa
2012-09-27 12:40 ` Glauber Costa
2012-09-27 12:40 ` Glauber Costa
2012-09-27 12:54 ` Michal Hocko
2012-09-27 12:54 ` Michal Hocko
2012-09-27 14:28 ` Mel Gorman
2012-09-27 14:28 ` Mel Gorman
2012-09-27 14:28 ` Mel Gorman
2012-09-27 14:49 ` Tejun Heo
2012-09-27 14:49 ` Tejun Heo
2012-09-27 14:57 ` Glauber Costa
2012-09-27 14:57 ` Glauber Costa
2012-09-27 17:46 ` Tejun Heo
2012-09-27 17:46 ` Tejun Heo
2012-09-27 17:46 ` Tejun Heo
2012-09-27 17:56 ` Michal Hocko
2012-09-27 17:56 ` Michal Hocko
2012-09-27 18:45 ` Glauber Costa
2012-09-27 18:45 ` Glauber Costa
2012-09-30 7:57 ` Tejun Heo
2012-09-30 7:57 ` Tejun Heo
2012-09-30 7:57 ` Tejun Heo
2012-09-30 8:02 ` Tejun Heo
2012-09-30 8:02 ` Tejun Heo
2012-09-30 8:56 ` James Bottomley
2012-09-30 8:56 ` James Bottomley
2012-09-30 8:56 ` James Bottomley
2012-09-30 10:37 ` Tejun Heo
2012-09-30 10:37 ` Tejun Heo
2012-09-30 10:37 ` Tejun Heo
2012-09-30 11:25 ` James Bottomley
2012-09-30 11:25 ` James Bottomley
2012-10-01 0:57 ` Tejun Heo
2012-10-01 0:57 ` Tejun Heo
2012-10-01 0:57 ` Tejun Heo
2012-10-01 8:43 ` Glauber Costa
2012-10-01 8:43 ` Glauber Costa
2012-10-01 8:46 ` Glauber Costa
2012-10-01 8:46 ` Glauber Costa
2012-10-03 22:59 ` Tejun Heo
2012-10-03 22:59 ` Tejun Heo
2012-10-01 8:36 ` Glauber Costa
2012-10-01 8:36 ` Glauber Costa
2012-09-27 12:08 ` Michal Hocko
2012-09-27 12:08 ` Michal Hocko
2012-09-27 12:08 ` Michal Hocko
2012-09-27 12:11 ` Glauber Costa
2012-09-27 12:11 ` Glauber Costa
2012-09-27 14:33 ` Tejun Heo
2012-09-27 14:33 ` Tejun Heo
2012-09-27 14:43 ` Mel Gorman
2012-09-27 14:43 ` Mel Gorman
2012-09-27 14:43 ` Mel Gorman
2012-09-27 14:58 ` Tejun Heo [this message]
2012-09-27 14:58 ` Tejun Heo
2012-09-27 18:30 ` Glauber Costa
2012-09-27 18:30 ` Glauber Costa
2012-09-30 8:23 ` Tejun Heo
2012-09-30 8:23 ` Tejun Heo
2012-10-01 8:45 ` Glauber Costa
2012-10-01 8:45 ` Glauber Costa
2012-10-03 22:54 ` Tejun Heo
2012-10-03 22:54 ` Tejun Heo
2012-10-04 11:55 ` Glauber Costa
2012-10-04 11:55 ` Glauber Costa
2012-10-06 2:19 ` Tejun Heo
2012-10-06 2:19 ` Tejun Heo
2012-10-06 2:19 ` Tejun Heo
2012-09-27 15:09 ` Michal Hocko
2012-09-27 15:09 ` Michal Hocko
2012-09-30 8:47 ` Tejun Heo
2012-09-30 8:47 ` Tejun Heo
2012-10-01 9:27 ` Michal Hocko
2012-10-01 9:27 ` Michal Hocko
2012-10-03 22:43 ` Tejun Heo
2012-10-03 22:43 ` Tejun Heo
2012-10-03 22:43 ` Tejun Heo
2012-10-05 13:47 ` Michal Hocko
2012-10-05 13:47 ` Michal Hocko
2012-10-05 13:47 ` Michal Hocko
2012-09-26 22:11 ` Johannes Weiner
2012-09-26 22:11 ` Johannes Weiner
2012-09-26 22:11 ` Johannes Weiner
2012-09-26 22:45 ` Glauber Costa
2012-09-26 22:45 ` Glauber Costa
2012-09-18 14:04 ` [PATCH v3 05/13] Add a __GFP_KMEMCG flag Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-18 14:15 ` Rik van Riel
2012-09-18 14:15 ` Rik van Riel
2012-09-18 15:06 ` Christoph Lameter
2012-09-18 15:06 ` Christoph Lameter
2012-09-18 15:06 ` Christoph Lameter
2012-09-19 7:39 ` Glauber Costa
2012-09-19 7:39 ` Glauber Costa
2012-09-19 7:39 ` Glauber Costa
2012-09-19 14:07 ` Christoph Lameter
2012-09-19 14:07 ` Christoph Lameter
2012-09-19 14:07 ` Christoph Lameter
2012-09-27 13:34 ` Mel Gorman
2012-09-27 13:34 ` Mel Gorman
2012-09-27 13:41 ` Glauber Costa
2012-09-27 13:41 ` Glauber Costa
2012-10-01 19:09 ` Johannes Weiner
2012-10-01 19:09 ` Johannes Weiner
2012-09-18 14:04 ` [PATCH v3 06/13] memcg: kmem controller infrastructure Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-20 16:05 ` JoonSoo Kim
2012-09-20 16:05 ` JoonSoo Kim
2012-09-20 16:05 ` JoonSoo Kim
2012-09-21 8:41 ` Glauber Costa
2012-09-21 8:41 ` Glauber Costa
2012-09-21 8:41 ` Glauber Costa
2012-09-21 9:14 ` JoonSoo Kim
2012-09-21 9:14 ` JoonSoo Kim
2012-09-26 15:51 ` Michal Hocko
2012-09-26 15:51 ` Michal Hocko
2012-09-26 15:51 ` Michal Hocko
2012-09-27 11:31 ` Glauber Costa
2012-09-27 11:31 ` Glauber Costa
2012-09-27 13:44 ` Michal Hocko
2012-09-27 13:44 ` Michal Hocko
2012-09-27 13:44 ` Michal Hocko
2012-09-28 11:34 ` Glauber Costa
2012-09-28 11:34 ` Glauber Costa
2012-09-28 11:34 ` Glauber Costa
2012-09-30 8:25 ` Tejun Heo
2012-09-30 8:25 ` Tejun Heo
2012-10-01 8:28 ` Glauber Costa
2012-10-01 8:28 ` Glauber Costa
2012-10-03 22:11 ` Tejun Heo
2012-10-03 22:11 ` Tejun Heo
2012-10-03 22:11 ` Tejun Heo
2012-10-01 9:44 ` Michal Hocko
2012-10-01 9:44 ` Michal Hocko
2012-10-01 9:44 ` Michal Hocko
2012-10-01 9:48 ` Michal Hocko
2012-10-01 9:48 ` Michal Hocko
2012-10-01 9:48 ` Michal Hocko
2012-10-01 10:09 ` Glauber Costa
2012-10-01 10:09 ` Glauber Costa
2012-10-01 11:51 ` Michal Hocko
2012-10-01 11:51 ` Michal Hocko
2012-10-01 11:51 ` Glauber Costa
2012-10-01 11:51 ` Glauber Costa
2012-10-01 11:51 ` Glauber Costa
2012-10-01 11:58 ` Michal Hocko
2012-10-01 11:58 ` Michal Hocko
2012-10-01 12:04 ` Glauber Costa
2012-10-01 12:04 ` Glauber Costa
2012-10-01 12:04 ` Glauber Costa
2012-09-18 14:04 ` [PATCH v3 07/13] mm: Allocate kernel pages to the right memcg Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-27 13:50 ` Mel Gorman
2012-09-27 13:50 ` Mel Gorman
2012-09-28 9:43 ` Glauber Costa
2012-09-28 9:43 ` Glauber Costa
2012-09-28 9:43 ` Glauber Costa
2012-09-28 13:28 ` Mel Gorman
2012-09-28 13:28 ` Mel Gorman
2012-09-27 13:52 ` Michal Hocko
2012-09-27 13:52 ` Michal Hocko
2012-09-27 13:52 ` Michal Hocko
2012-09-18 14:04 ` [PATCH v3 08/13] res_counter: return amount of charges after res_counter_uncharge Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-10-01 10:00 ` Michal Hocko
2012-10-01 10:00 ` Michal Hocko
2012-10-01 10:01 ` Glauber Costa
2012-10-01 10:01 ` Glauber Costa
2012-09-18 14:04 ` [PATCH v3 09/13] memcg: kmem accounting lifecycle management Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-10-01 12:15 ` Michal Hocko
2012-10-01 12:15 ` Michal Hocko
2012-10-01 12:15 ` Michal Hocko
2012-10-01 12:29 ` Glauber Costa
2012-10-01 12:29 ` Glauber Costa
2012-10-01 12:29 ` Glauber Costa
2012-10-01 12:36 ` Michal Hocko
2012-10-01 12:36 ` Michal Hocko
2012-10-01 12:36 ` Michal Hocko
2012-10-01 12:43 ` Glauber Costa
2012-10-01 12:43 ` Glauber Costa
2012-10-01 12:43 ` Glauber Costa
2012-09-18 14:04 ` [PATCH v3 10/13] memcg: use static branches when code not in use Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-10-01 12:25 ` Michal Hocko
2012-10-01 12:25 ` Michal Hocko
2012-10-01 12:27 ` Glauber Costa
2012-10-01 12:27 ` Glauber Costa
2012-10-01 12:27 ` Glauber Costa
2012-09-18 14:04 ` [PATCH v3 11/13] memcg: allow a memcg with kmem charges to be destructed Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-10-01 12:30 ` Michal Hocko
2012-10-01 12:30 ` Michal Hocko
2012-10-01 12:30 ` Michal Hocko
2012-09-18 14:04 ` [PATCH v3 12/13] execute the whole memcg freeing in rcu callback Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-21 17:23 ` Tejun Heo
2012-09-21 17:23 ` Tejun Heo
2012-09-21 17:23 ` Tejun Heo
2012-09-24 8:48 ` Glauber Costa
2012-09-24 8:48 ` Glauber Costa
2012-09-24 8:48 ` Glauber Costa
2012-10-01 13:27 ` Michal Hocko
2012-10-01 13:27 ` Michal Hocko
2012-10-01 13:27 ` Michal Hocko
2012-10-04 10:53 ` Glauber Costa
2012-10-04 10:53 ` Glauber Costa
2012-10-04 10:53 ` Glauber Costa
2012-10-04 14:20 ` Glauber Costa
2012-10-04 14:20 ` Glauber Costa
2012-10-05 15:31 ` Johannes Weiner
2012-10-05 15:31 ` Johannes Weiner
2012-10-05 15:31 ` Johannes Weiner
2012-10-08 9:45 ` Glauber Costa
2012-10-08 9:45 ` Glauber Costa
2012-09-18 14:04 ` [PATCH v3 13/13] protect architectures where THREAD_SIZE >= PAGE_SIZE against fork bombs Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-09-18 14:04 ` Glauber Costa
2012-10-01 13:17 ` Michal Hocko
2012-10-01 13:17 ` Michal Hocko
2012-10-01 13:17 ` 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=20120927145802.GC4251@mtj.dyndns.org \
--to=tj@kernel.org \
--cc=cgroups@vger.kernel.org \
--cc=devel@openvz.org \
--cc=fweisbec@gmail.com \
--cc=glommer@parallels.com \
--cc=hannes@cmpxchg.org \
--cc=kamezawa.hiroyu@jp.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@suse.de \
--cc=mhocko@suse.cz \
--cc=rientjes@google.com \
--cc=suleiman@google.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.