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Date: Sun, 18 Sep 2011 17:40:11 -0300
From: Glauber Costa <glommer@parallels.com>
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To: "Kirill A. Shutemov" <kirill@shutemov.name>
CC: <linux-kernel@vger.kernel.org>, <paul@paulmenage.org>,
        <lizf@cn.fujitsu.com>, <kamezawa.hiroyu@jp.fujitsu.com>,
        <ebiederm@xmission.com>, <davem@davemloft.net>, <gthelen@google.com>,
        <netdev@vger.kernel.org>, <linux-mm@kvack.org>
Subject: Re: [PATCH v2 1/7] Basic kernel memory functionality for the Memory
 Controller
References: <1316051175-17780-1-git-send-email-glommer@parallels.com> <1316051175-17780-2-git-send-email-glommer@parallels.com> <20110917174535.GA1658@shutemov.name> <4E7567E0.9010401@parallels.com> <20110918190509.GC28057@shutemov.name> <4E764259.5070209@parallels.com> <20110918203931.GA28611@shutemov.name>
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On 09/18/2011 05:39 PM, Kirill A. Shutemov wrote:
> On Sun, Sep 18, 2011 at 04:11:21PM -0300, Glauber Costa wrote:
>> On 09/18/2011 04:05 PM, Kirill A. Shutemov wrote:
>>> On Sun, Sep 18, 2011 at 12:39:12AM -0300, Glauber Costa wrote:
>>>>> Always zero in root cgroup?
>>>>
>>>> Yes, if we're not accounting, it should be zero. WARN_ON, maybe?
>>>
>>> -ENOSYS?
>>>
>> I'd personally prefer WARN_ON. It is good symmetry from userspace PoV to
>> always be able to get a value out of it. Also, it something goes wrong
>> and it is not zero for some reason, this will help us find it.
>
> What's the point to get non-relevant value?
> What about -ENOSYS + WARN_ON?
>
Well,

what about not even registering kernel memory files for !root cgroup?