From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dmitry Potapov <dpotapov@gmail.com>
Subject: Re: [PATCH] don't use mmap() to hash files
Date: Mon, 15 Feb 2010 15:25:27 +0300
Message-ID: <37fcd2781002150425od069e75ueaff424e2357d78b@mail.gmail.com>
References: <20100211234753.22574.48799.reportbug@gibbs.hungrycats.org>
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	 <37fcd2781002141106v761ce6e0kc5c5bdd5001f72a9@mail.gmail.com>
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	 <alpine.DEB.1.00.1002142025160.20986@pacific.mpi-cbg.de>
	 <37fcd2781002141156n7e2b9673s1eb6c12869facdb2@mail.gmail.com>
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Cc: Johannes Schindelin <Johannes.Schindelin@gmx.de>,
	Zygo Blaxell <zblaxell@esightcorp.com>,
	Ilari Liusvaara <ilari.liusvaara@elisanet.fi>,
	Thomas Rast <trast@student.ethz.ch>,
	Jonathan Nieder <jrnieder@gmail.com>, git@vger.kernel.org
To: Paolo Bonzini <bonzini@gnu.org>
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On Mon, Feb 15, 2010 at 10:48 AM, Paolo Bonzini <bonzini@gnu.org> wrote:
> On 02/14/2010 08:56 PM, Dmitry Potapov wrote:
>>
>> It may not work without enough swap space
>
> No, the kernel will use the file itself as "swap" if it has to page out the
> memory (since the mmap is PROT_READ).

I was speaking about read(), when the whole file is read  in memory. In
this case, you are going to use a lot of "swap" and it is not pretty...
That's why I said maybe we should have an option here...


Dmitry