Date: Wed, 2 May 2007 21:34:51 +0100 (BST)
From: Hugh Dickins <hugh@veritas.com>
To: Phillip Susi <psusi@cfl.rr.com>
cc: =?UTF-8?B?QmrDtnJuIFN0ZWluYnJpbms=?= <B.Steinbrink@gmx.de>,
       Linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: Execute in place
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On Wed, 2 May 2007, Phillip Susi wrote:
> Hugh Dickins wrote:
> > tmpfs doesn't store its stuff in the page cache twice: that's true,
> > and I didn't mean to imply otherwise.  But tmpfs doesn't contain any
> > support for rom memory: you'd have to copy from rom to tmpfs to use it.
> 
> The question is, when you execute a binary on tmpfs, does its code segment get
> mapped directly where it's at in the buffer cache, or does it get copied to
> another page for the executing process?  At least, assuming this is possible
> due to the vma and file offsets of the segment being aligned.

Its pages are mapped directly into the executing process, without copying.

Hugh
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