From: Glauber Costa <glommer@parallels.com>
To: Michal Hocko <mhocko@suse.cz>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Andrew Morton <akpm@linux-foundation.org>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>, Tejun Heo <tj@kernel.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>
Subject: Re: [PATCH 5/7] memcg: get rid of once-per-second cache shrinking for dead memcgs
Date: Fri, 16 Nov 2012 19:50:41 +0400 [thread overview]
Message-ID: <50A660D1.7020001@parallels.com> (raw)
In-Reply-To: <20121116145508.GC2006@dhcp22.suse.cz>
On 11/16/2012 06:55 PM, Michal Hocko wrote:
> On Fri 16-11-12 16:21:59, KAMEZAWA Hiroyuki wrote:
>> (2012/11/16 16:11), Glauber Costa wrote:
>>> On 11/16/2012 09:07 AM, Kamezawa Hiroyuki wrote:
>>>> (2012/11/15 22:47), Glauber Costa wrote:
>>>>> On 11/15/2012 01:41 PM, Kamezawa Hiroyuki wrote:
>>>>>> (2012/11/15 11:54), Glauber Costa wrote:
>>>>>>> The idea is to synchronously do it, leaving it up to the shrinking
>>>>>>> facilities in vmscan.c and/or others. Not actively retrying shrinking
>>>>>>> may leave the caches alive for more time, but it will remove the ugly
>>>>>>> wakeups. One would argue that if the caches have free objects but are
>>>>>>> not being shrunk, it is because we don't need that memory yet.
>>>>>>>
>>>>>>> Signed-off-by: Glauber Costa <glommer@parallels.com>
>>>>>>> CC: Michal Hocko <mhocko@suse.cz>
>>>>>>> CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>>>>>>> CC: Johannes Weiner <hannes@cmpxchg.org>
>>>>>>> CC: Andrew Morton <akpm@linux-foundation.org>
>>>>>>
>>>>>> I agree this patch but can we have a way to see the number of unaccounted
>>>>>> zombie cache usage for debugging ?
>>>>>>
>>>>>> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>>>>>>
>>>>> Any particular interface in mind ?
>>>>>
>>>>
>>>> Hmm, it's debug interface and having cgroup file may be bad.....
>>>> If it can be seen in bytes or some, /proc/vmstat ?
>>>>
>>>> out_of_track_slabs xxxxxxx. hm ?
>>>>
>>>
>>> I particularly think that, being this a debug interface, it is also
>>> useful to have an indication of which caches are still in place. This is
>>> because the cache itself, is the best indication we have about the
>>> specific workload that may be keeping it in memory.
>>>
>>> I first thought debugfs could help us probing useful information out of
>>> it, but given all the abuse people inflicted in debugfs... maybe we
>>> could have a file in the root memcg with that information for all
>>> removed memcgs? If we do that, we can go further and list the memcgs
>>> that are pending due to memsw as well. memory.dangling_memcgs ?
>>>
>>
>> Hm, I'm ok with it... others ?
>
> What about memory.kmem.dangling_caches?
>
If that is what it does, sure.
But as I said, kmem is not the only thing that can keep caches in
memory. If we're going for this, maybe we should be more comprehensive
and show it all.
next prev parent reply other threads:[~2012-11-16 15:50 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-15 2:54 [PATCH 0/7] fixups for kmemcg Glauber Costa
2012-11-15 0:47 ` David Rientjes
2012-11-15 2:54 ` [PATCH 1/7] memcg: simplify ida initialization Glauber Costa
2012-11-15 2:54 ` [PATCH 2/7] move include of workqueue.h to top of slab.h file Glauber Costa
2012-11-15 9:30 ` Kamezawa Hiroyuki
2012-11-15 2:54 ` [PATCH 3/7] memcg: remove test for current->mm in memcg_stop/resume_kmem_account Glauber Costa
2012-11-15 9:28 ` Kamezawa Hiroyuki
2012-11-15 2:54 ` [PATCH 4/7] memcg: replace __always_inline with plain inline Glauber Costa
2012-11-15 9:29 ` Kamezawa Hiroyuki
2012-11-15 2:54 ` [PATCH 5/7] memcg: get rid of once-per-second cache shrinking for dead memcgs Glauber Costa
2012-11-15 9:41 ` Kamezawa Hiroyuki
2012-11-15 13:47 ` Glauber Costa
2012-11-16 5:07 ` Kamezawa Hiroyuki
2012-11-16 7:11 ` Glauber Costa
2012-11-16 7:21 ` Kamezawa Hiroyuki
2012-11-16 14:55 ` Michal Hocko
2012-11-16 15:50 ` Glauber Costa [this message]
2012-11-15 2:54 ` [PATCH 6/7] memcg: add comments clarifying aspects of cache attribute propagation Glauber Costa
2012-11-15 2:54 ` [PATCH 7/7] slub: drop mutex before deleting sysfs entry Glauber Costa
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