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Date: Tue, 7 Oct 2008 17:54:12 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
       "Kirill A. Shutemov" <kirill@shutemov.name>,
       Andi Kleen <andi@firstfloor.org>, Ingo Molnar <mingo@redhat.com>,
       Arjan van de Ven <arjan@infradead.org>, Hugh Dickins <hugh@veritas.com>,
       KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
       Ulrich Drepper <drepper@redhat.com>,
       Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH, v3] shmat: introduce flag SHM_MAP_NOT_FIXED
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On Tue,  7 Oct 2008 19:15:17 +0300
"Kirill A. Shutemov" <kirill@shutemov.name> wrote:

> If SHM_MAP_NOT_FIXED specified and shmaddr is not NULL, then the kernel takes
> shmaddr as a hint about where to place the mapping. The address of the mapping
> is returned as the result of the call.
> 
> It's similar to mmap() without MAP_FIXED.

NAK

This is a pointless API extension tacked onto a historic interface that
isn't well designed.

Use shm_open, and mmap and you get the functionality required using
modern posix interfaces with *NO* Linux extensions involved.

Alan