Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933469AbZDASM4 (ORCPT ); Wed, 1 Apr 2009 14:12:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933108AbZDASMo (ORCPT ); Wed, 1 Apr 2009 14:12:44 -0400 Received: from smtp.ultrahosting.com ([74.213.174.254]:56423 "EHLO smtp.ultrahosting.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765729AbZDASMn (ORCPT ); Wed, 1 Apr 2009 14:12:43 -0400 Date: Wed, 1 Apr 2009 14:06:12 -0400 (EDT) From: Christoph Lameter X-X-Sender: cl@qirst.com To: Ingo Molnar 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 In-Reply-To: <20090401154913.GA31435@elte.hu> Message-ID: 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> <20090401154913.GA31435@elte.hu> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 777 Lines: 18 On Wed, 1 Apr 2009, Ingo Molnar wrote: > > 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. Better leave as is. __read_mostly is for hot code paths. __read_mostly should be packed as tightly as possible to increase the chance that one cacheline includes multiple of the critical variables for the hot code paths. Too much __read_mostly defeats its purpose. -- 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/