Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761173AbZDAPy0 (ORCPT ); Wed, 1 Apr 2009 11:54:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756949AbZDAPyP (ORCPT ); Wed, 1 Apr 2009 11:54:15 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:56308 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756399AbZDAPyO (ORCPT ); Wed, 1 Apr 2009 11:54:14 -0400 Date: Wed, 1 Apr 2009 17:49:13 +0200 From: Ingo Molnar To: Christoph Lameter Cc: Tejun Heo , Martin Schwidefsky , rusty@rustcorp.com.au, tglx@linutronix.de, x86@kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, Paul Mundt , rmk@arm.linux.org.uk, starvik@axis.com, ralf@linux-mips.org, davem@davemloft.net, cooloney@kernel.org, kyle@mcmartin.ca, matthew@wil.cx, grundler@parisc-linux.org, takata@linux-m32r.org, benh@kernel.crashing.org, rth@twiddle.net, ink@jurassic.park.msu.ru, heiko.carstens@de.ibm.com, Linus Torvalds , Nick Piggin Subject: Re: [PATCH UPDATED] percpu: use dynamic percpu allocator as the default percpu allocator Message-ID: <20090401154913.GA31435@elte.hu> References: <20090325122738.42d105b7@skybase> <49CA1AC3.9080908@kernel.org> <20090325150035.541e707a@skybase> <49CA3C2C.5030702@kernel.org> <49D099F0.3000807@kernel.org> <20090330114938.GB10070@elte.hu> <49D2B209.9060000@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1024 Lines: 26 * Christoph Lameter wrote: > On Wed, 1 Apr 2009, Tejun Heo wrote: > > > > 1. Lot of unnecessary use of __read_mostly for local static variables that > > > are not on the hotpath. Patch follows in this message. > > > > Hmmm... Those are basically read-only vars once initialization is > > complete. IIUC, __read_mostly just puts the tagged variables into a > > separate segment so that they don't have to worry about cacheline > > bouncing. Is there any reason to remove __read_mostly? Or is it just > > that it's mostly superflous? > > Yes its better for the variables to be all together if its not on hot > cache paths. And its better to keep the __read_mostly segment reserved for > frequently accessed variables. We need __access_rarely i guess. Ingo -- 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/