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From: "Manfred Spraul" <manfred@colorfullife.com>
To: "Jamie Lokier" <lk@tantalophile.demon.co.uk>
Cc: <linux-kernel@vger.kernel.org>
In-Reply-To: <000201c0a71f$3a48fae0$5517fea9@local> <20010307171020.A10607@pcep-jamie.cern.ch>
Subject: Re: Hashing and directories
Date: Wed, 7 Mar 2001 17:23:26 +0100
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From: "Jamie Lokier" <lk@tantalophile.demon.co.uk>
> Manfred Spraul wrote:
> > I'm not sure that this is the right way: It means that every exec()
> > must call dup_mmap(), and usually only to copy a few hundert
> > bytes. But I don't see a sane alternative. I won't propose to
> > create a temporary file in a kernel tmpfs mount ;-)
>
> Every exec creates a whole new mm anyway, after copying data from the
> old mm.  The suggestion is to create the new mm before copying the
> data, and to copy the data from the old mm directly to the new one.
>

exec_mmap currenly avoids mm_alloc()/activate_mm()/mm_drop() for single
threaded apps, and that would become impossible.
I'm not sure how expensive these calls are.

--
    Manfred


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