netdev - Re: [PATCH v3 2/7] socket: initial cgroup code.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4E7DDDE5.6050001@parallels.com>
Date:	Sat, 24 Sep 2011 10:40:53 -0300
From:	Glauber Costa <glommer@...allels.com>
To:	Balbir Singh <bsingharora@...il.com>
CC:	Greg Thelen <gthelen@...gle.com>, <linux-kernel@...r.kernel.org>,
	<paul@...lmenage.org>, <lizf@...fujitsu.com>,
	<kamezawa.hiroyu@...fujitsu.com>, <ebiederm@...ssion.com>,
	<davem@...emloft.net>, <netdev@...r.kernel.org>,
	<linux-mm@...ck.org>, <kirill@...temov.name>
Subject: Re: [PATCH v3 2/7] socket: initial cgroup code.

On 09/22/2011 12:09 PM, Balbir Singh wrote:
> On Thu, Sep 22, 2011 at 11:30 AM, Greg Thelen<gthelen@...gle.com>  wrote:
>> On Wed, Sep 21, 2011 at 11:59 AM, Glauber Costa<glommer@...allels.com>  wrote:
>>> Right now I am working under the assumption that tasks are long lived inside
>>> the cgroup. Migration potentially introduces some nasty locking problems in
>>> the mem_schedule path.
>>>
>>> Also, unless I am missing something, the memcg already has the policy of
>>> not carrying charges around, probably because of this very same complexity.
>>>
>>> True that at least it won't EBUSY you... But I think this is at least a way
>>> to guarantee that the cgroup under our nose won't disappear in the middle of
>>> our allocations.
>>
>> Here's the memcg user page behavior using the same pattern:
>>
>> 1. user page P is allocate by task T in memcg M1
>> 2. T is moved to memcg M2.  The P charge is left behind still charged
>> to M1 if memory.move_charge_at_immigrate=0; or the charge is moved to
>> M2 if memory.move_charge_at_immigrate=1.
>> 3. rmdir M1 will try to reclaim P (if P was left in M1).  If unable to
>> reclaim, then P is recharged to parent(M1).
>>
>
> We also have some magic in page_referenced() to remove pages
> referenced from different containers. What we do is try not to
> penalize a cgroup if another cgroup is referencing this page and the
> page under consideration is being reclaimed from the cgroup that
> touched it.
>
> Balbir Singh
Btw:

This has the same problem we'll face for any kmem related memory in the 
cgroup: We can't just force reclaim to make the cgroup empty...
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html