From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 8 Oct 2008 11:20:37 +0100 From: Alan Cox Subject: Re: [PATCH, v3] shmat: introduce flag SHM_MAP_NOT_FIXED Message-ID: <20081008112037.6fa37c0b@lxorguk.ukuu.org.uk> In-Reply-To: <20081008091112.GK7971@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> <20081008093424.4e88a3c2@lxorguk.ukuu.org.uk> <20081008084350.GI7971@one.firstfloor.org> <20081008095851.01790b6a@lxorguk.ukuu.org.uk> <20081008091112.GK7971@one.firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT 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: > That is racy when multi threaded because shmat() doesn't replace, so you > would need to munmap() inbetween and someone else could steal the area > then. Yes you could stick a loop around it. It could livelock. > No, it's not a good interface I would advocate. You could just use pthread mutexes in your application. The rA'le of the kernel is not to provide nappies for people who think programming is too hard but to provide services that can be used to build applications. 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