From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: Michel Lespinasse <walken@google.com>
Subject: Re: [RFC] mlock: release mmap_sem every 256 faulted pages
Cc: kosaki.motohiro@jp.fujitsu.com, Andrew Morton <akpm@linux-foundation.org>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        Hugh Dickins <hugh.dickins@tiscali.co.uk>,
        Nick Piggin <npiggin@kernel.dk>, Rik van Riel <riel@redhat.com>
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References: <20101122215746.e847742d.akpm@linux-foundation.org> <AANLkTi=dK9wQaHm=tXOCqN2BDw5jEtH5qfs9zRHbE0qT@mail.gmail.com>
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Date: Wed, 24 Nov 2010 08:57:56 +0900 (JST)
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> > A more compelling description of why this problem needs addressing
> > would help things along.
> 
> Oh my. It's probably not too useful for desktops, where such large
> mlocks are hopefully uncommon.
> 
> At google we have many applications that serve data from memory and
> don't want to allow for disk latencies. Some of the simpler ones use
> mlock (though there are other ways - anon memory running with swap
> disabled is a surprisingly popular choice).
> 
> Kosaki is also showing interest in mlock, though I'm not sure what his
> use case is.

I don't have any solid use case. Usually server app only do mlock anonymous memory.
But, I haven't found any negative effect in your proposal, therefore I hope to help
your effort as I always do when the proposal don't have negative impact.


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