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Date: Mon, 19 Dec 2011 10:39:54 +0000
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Anton Vorontsov <anton.vorontsov@linaro.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
        Arve =?ISO-8859-1?B?SGr4bm5lduVn?= <arve@android.com>,
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        John Stultz <john.stultz@linaro.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: Android low memory killer vs. memory pressure notifications
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>   The main downside of this approach is that mem_cg needs 20 bytes per
>   page (on a 32 bit machine). So on a 32 bit machine with 4K pages
>   that's approx. 0.5% of RAM, or, in other words, 5MB on a 1GB machine.

The obvious question would be why? Would fixing memcg make more sense ?

The only problem I see with having a user space manager is that manager
probably has to be mlock to avoid awkward fail cases and that may in fact
make it smaller kernel side.