Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261934AbVAQQNt (ORCPT ); Mon, 17 Jan 2005 11:13:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262033AbVAQQNt (ORCPT ); Mon, 17 Jan 2005 11:13:49 -0500 Received: from [213.146.154.40] ([213.146.154.40]:61657 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S261934AbVAQQNr (ORCPT ); Mon, 17 Jan 2005 11:13:47 -0500 Date: Mon, 17 Jan 2005 16:13:35 +0000 From: Christoph Hellwig To: Robert Wisniewski Cc: Arjan van de Ven , Andrew Morton , karim@opersys.com, hch@infradead.org, tglx@linutronix.de, linux-kernel@vger.kernel.org Subject: Re: 2.6.11-rc1-mm1 Message-ID: <20050117161335.GA9404@infradead.org> Mail-Followup-To: Christoph Hellwig , Robert Wisniewski , Arjan van de Ven , Andrew Morton , karim@opersys.com, tglx@linutronix.de, linux-kernel@vger.kernel.org References: <20050114002352.5a038710.akpm@osdl.org> <1105740276.8604.83.camel@tglx.tec.linutronix.de> <41E85123.7080005@opersys.com> <20050116162127.GC26144@infradead.org> <41EAC560.30202@opersys.com> <16874.50688.68959.36156@kix.watson.ibm.com> <20050116123212.1b22495b.akpm@osdl.org> <16874.54187.919814.272833@kix.watson.ibm.com> <1105911624.8734.55.camel@laptopd505.fenrus.org> <16875.56543.264481.586616@kix.watson.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <16875.56543.264481.586616@kix.watson.ibm.com> User-Agent: Mutt/1.4.1i X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1172 Lines: 21 On Mon, Jan 17, 2005 at 10:48:52AM -0500, Robert Wisniewski wrote: > Wow - disabling interrupts is handfuls to tens of cycles, so that means > some architectures take thousands of cycles to do atomic operations. Then > I would definitely agree we should not be using atomic operations on those, > fwiw, out of curiosity, what archs make atomic ops so expensive. > > Andrew, on the broader note. If the community feels disabling interrupts > is the better way to go for the variables (I think it's index and count) we > were protecting with atomic ops then as the code stands things should be > fine with that approach and we can make that change. The thing I'm unhappy with is what the code does currently. I haven't looked at the code enough nor through about the problem enough to tell you what's the right thing to do. Knowing that will involve review of the architecture and serious benchmarking on a few plattforms. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/