From: Glauber Costa <glommer@parallels.com>
To: Tejun Heo <tj@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>, <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>,
Mel Gorman <mgorman@suse.de>,
David Rientjes <rientjes@google.com>,
Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [PATCH v3 04/13] kmem accounting basic infrastructure
Date: Wed, 26 Sep 2012 21:36:36 +0400 [thread overview]
Message-ID: <50633D24.6020002@parallels.com> (raw)
In-Reply-To: <20120926163648.GO16296@google.com>
On 09/26/2012 08:36 PM, Tejun Heo wrote:
> Hello, Michal, Glauber.
>
> On Wed, Sep 26, 2012 at 04:03:47PM +0200, Michal Hocko wrote:
>> Haven't we already discussed that a new memcg should inherit kmem_accounted
>> from its parent for use_hierarchy?
>> Say we have
>> root
>> |
>> A (kmem_accounted = 1, use_hierachy = 1)
>> \
>> B (kmem_accounted = 0)
>> \
>> C (kmem_accounted = 1)
>>
>> B find's itself in an awkward situation becuase it doesn't want to
>> account u+k but it ends up doing so becuase C.
>
> Do we really want this level of flexibility? What's wrong with a
> global switch at the root? I'm not even sure we want this to be
> optional at all. The only reason I can think of is that it might
> screw up some configurations in use which are carefully crafted to
> suit userland-only usage but for that isn't what we need a transition
> plan rather than another ultra flexible config option that not many
> really understand the implication of?
>
> In the same vein, do we really need both .kmem_accounted and config
> option? If someone is turning on MEMCG, just include kmem accounting.
>
Yes, we do.
This was discussed multiple times. Our interest is to preserve existing
deployed setup, that were tuned in a world where kmem didn't exist.
Because we also feed kmem to the user counter, this may very well
disrupt their setup.
User memory, unlike kernel memory, may very well be totally in control
of the userspace application, so it is not unreasonable to believe that
extra pages appearing in a new kernel version may break them.
It is actually a much worse compatibility problem than flipping
hierarchy, in comparison
WARNING: multiple messages have this Message-ID (diff)
From: Glauber Costa <glommer@parallels.com>
To: Tejun Heo <tj@kernel.org>
Cc: Michal Hocko <mhocko@suse.cz>,
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>,
Mel Gorman <mgorman@suse.de>,
David Rientjes <rientjes@google.com>,
Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [PATCH v3 04/13] kmem accounting basic infrastructure
Date: Wed, 26 Sep 2012 21:36:36 +0400 [thread overview]
Message-ID: <50633D24.6020002@parallels.com> (raw)
In-Reply-To: <20120926163648.GO16296@google.com>
On 09/26/2012 08:36 PM, Tejun Heo wrote:
> Hello, Michal, Glauber.
>
> On Wed, Sep 26, 2012 at 04:03:47PM +0200, Michal Hocko wrote:
>> Haven't we already discussed that a new memcg should inherit kmem_accounted
>> from its parent for use_hierarchy?
>> Say we have
>> root
>> |
>> A (kmem_accounted = 1, use_hierachy = 1)
>> \
>> B (kmem_accounted = 0)
>> \
>> C (kmem_accounted = 1)
>>
>> B find's itself in an awkward situation becuase it doesn't want to
>> account u+k but it ends up doing so becuase C.
>
> Do we really want this level of flexibility? What's wrong with a
> global switch at the root? I'm not even sure we want this to be
> optional at all. The only reason I can think of is that it might
> screw up some configurations in use which are carefully crafted to
> suit userland-only usage but for that isn't what we need a transition
> plan rather than another ultra flexible config option that not many
> really understand the implication of?
>
> In the same vein, do we really need both .kmem_accounted and config
> option? If someone is turning on MEMCG, just include kmem accounting.
>
Yes, we do.
This was discussed multiple times. Our interest is to preserve existing
deployed setup, that were tuned in a world where kmem didn't exist.
Because we also feed kmem to the user counter, this may very well
disrupt their setup.
User memory, unlike kernel memory, may very well be totally in control
of the userspace application, so it is not unreasonable to believe that
extra pages appearing in a new kernel version may break them.
It is actually a much worse compatibility problem than flipping
hierarchy, in comparison
--
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next prev parent reply other threads:[~2012-09-26 17:40 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 [this message]
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
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
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