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Date: Tue, 20 Dec 2011 18:30:41 -0800
From: Frank Rowand <frank.rowand@am.sony.com>
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To: Anton Vorontsov <anton.vorontsov@linaro.org>
CC: "Rowand, Frank" <Frank_Rowand@sonyusa.com>,
        David Rientjes <rientjes@google.com>,
        KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
        Michal Hocko <mhocko@suse.cz>,
        =?UTF-8?B?QXJ2ZSBIasO4bm5ldsOlZw==?= <arve@android.com>,
        Rik van Riel <riel@redhat.com>, Pavel Machek <pavel@ucw.cz>,
        Greg Kroah-Hartman <gregkh@suse.de>,
        Andrew Morton <akpm@linux-foundation.org>,
        John Stultz <john.stultz@linaro.org>,
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        Johannes Weiner <hannes@cmpxchg.org>,
        KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
        Alan Cox <alan@lxorguk.ukuu.org.uk>,
        "tbird20d@gmail.com" <tbird20d@gmail.com>
Subject: Re: Android low memory killer vs. memory pressure notifications
References: <20111219025328.GA26249@oksana.dev.rtsoft.ru> <20111219121255.GA2086@tiehlicka.suse.cz> <alpine.DEB.2.00.1112191110060.19949@chino.kir.corp.google.com> <20111220145654.GA26881@oksana.dev.rtsoft.ru> <alpine.DEB.2.00.1112201322170.22077@chino.kir.corp.google.com> <20111221002853.GA11504@oksana.dev.rtsoft.ru> <4EF132EA.7000300@am.sony.com> <20111221020723.GA5214@oksana.dev.rtsoft.ru>
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On 12/20/11 18:07, Anton Vorontsov wrote:
> On Tue, Dec 20, 2011 at 05:14:18PM -0800, Frank Rowand wrote:

< snip >

>> And for embedded and for real-time, some of us do not want cgroups to be
>> a mandatory thing.  We want it to remain configurable.  My personal
>> interest is in keeping the latency of certain critical paths (especially
>> in the scheduler) short and consistent.
> 
> Much thanks for your input! That would be quite strong argument for going
> with /dev/mem_notify approach. Do you have any specific numbers how cgroups
> makes scheduler latencies worse?

Sorry, I don't have specific numbers.  And the numbers would be workload
specific anyway.

-Frank