Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261561AbVCCGgB (ORCPT ); Thu, 3 Mar 2005 01:36:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261508AbVCCGfg (ORCPT ); Thu, 3 Mar 2005 01:35:36 -0500 Received: from gate.crashing.org ([63.228.1.57]:59348 "EHLO gate.crashing.org") by vger.kernel.org with ESMTP id S261550AbVCCGdT (ORCPT ); Thu, 3 Mar 2005 01:33:19 -0500 Subject: Re: Page fault scalability patch V18: Drop first acquisition of ptl From: Benjamin Herrenschmidt To: Nick Piggin Cc: "David S. Miller" , Paul Mackerras , Andrew Morton , clameter@sgi.com, Linux Kernel list , linux-ia64@vger.kernel.org, Anton Blanchard In-Reply-To: <42274727.2070200@yahoo.com.au> References: <20050302174507.7991af94.akpm@osdl.org> <20050302185508.4cd2f618.akpm@osdl.org> <20050302201425.2b994195.akpm@osdl.org> <16934.39386.686708.768378@cargo.ozlabs.ibm.com> <20050302213831.7e6449eb.davem@davemloft.net> <1109829248.5679.178.camel@gaston> <42274727.2070200@yahoo.com.au> Content-Type: text/plain Date: Thu, 03 Mar 2005 17:30:28 +1100 Message-Id: <1109831428.5680.187.camel@gaston> Mime-Version: 1.0 X-Mailer: Evolution 2.0.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 731 Lines: 21 On Fri, 2005-03-04 at 04:19 +1100, Nick Piggin wrote: > You don't want to do that for all architectures, as I said earlier. > eg. i386 can concurrently set the dirty bit with the MMU (which won't > honour the lock). > > So you then need an atomic lock, atomic pte operations, and atomic > unlock where previously you had only the atomic pte operation. This is > disastrous for performance. Of course, but I was answering to David about sparc64 which uses software TLB load :) Ben. - 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/