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.
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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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