From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 8 Oct 2008 09:33:25 +0100 From: Alan Cox Subject: Re: [PATCH, v3] shmat: introduce flag SHM_MAP_NOT_FIXED Message-ID: <20081008093325.3d0d3bd6@lxorguk.ukuu.org.uk> In-Reply-To: <20081007235737.GD7971@one.firstfloor.org> References: <1223396117-8118-1-git-send-email-kirill@shutemov.name> <2f11576a0810070931k79eb72dfr838a96650563b93a@mail.gmail.com> <20081007211038.GQ20740@one.firstfloor.org> <20081008000518.13f48462@lxorguk.ukuu.org.uk> <20081007232059.GU20740@one.firstfloor.org> <20081008004030.7a0e9915@lxorguk.ukuu.org.uk> <20081007235737.GD7971@one.firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Andi Kleen Cc: KOSAKI Motohiro , "Kirill A. Shutemov" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Ingo Molnar , Arjan van de Ven , Hugh Dickins , Ulrich Drepper , Andrew Morton List-ID: > Perhaps I'm confused but my /dev/shm doesn't have any such files, > but I see a variety of shm segments in ipcs. > > What would the path passed to shm_open look like? Well right now they don't get exposed as they are created unlinked but that is a trivial tweak to mm/shmem.c. > > and nobody is wanting to map those at fixed addresses. > > You're saying it should always use the address as a search hint? Nothing of the sort. I'm pointing out that mmap and shm_open already provide all the needed interfaces for this for real world applications today. > > Just changing the semantics unconditionally would seem risky to me. After > all as you point out they are primarily for compatibility and for that keeping > old semantics would seem better to me. We don't need to change any semantics, there is a perfectly good alternative standards based interface. At most you might want to make the sys3 shared memory segments appear in /dev/shm/ somewhere. Alan -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org