From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932239AbVKWTkx (ORCPT ); Wed, 23 Nov 2005 14:40:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932240AbVKWTkw (ORCPT ); Wed, 23 Nov 2005 14:40:52 -0500 Received: from fmr24.intel.com ([143.183.121.16]:49568 "EHLO scsfmr004.sc.intel.com") by vger.kernel.org with ESMTP id S932239AbVKWTkw (ORCPT ); Wed, 23 Nov 2005 14:40:52 -0500 Subject: Re: [PATCH]: Free pages from local pcp lists under tight memory conditions From: Rohit Seth To: Christoph Lameter Cc: akpm@osdl.org, torvalds@osdl.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org In-Reply-To: References: <20051122161000.A22430@unix-os.sc.intel.com> Content-Type: text/plain Organization: Intel Date: Wed, 23 Nov 2005 11:46:34 -0800 Message-Id: <1132775194.25086.54.camel@akash.sc.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.2.2 (2.2.2-5) Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 23 Nov 2005 19:39:36.0483 (UTC) FILETIME=[A2DF3F30:01C5F065] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2005-11-23 at 11:30 -0800, Christoph Lameter wrote: > On Tue, 22 Nov 2005, Rohit Seth wrote: > > > [PATCH]: This patch free pages (pcp->batch from each list at a time) from > > local pcp lists when a higher order allocation request is not able to > > get serviced from global free_list. > > Ummm.. One controversial idea: How about removing the complete pcp > subsystem? Last time we disabled pcps we saw that the effect > that it had was within noise ratio on AIM7. The lru lock taken without > pcp is in the local zone and thus rarely contended. Oh please stop. This per_cpu_pagelist is one great logic that has got added in allocator. Besides providing pages without the need to acquire the zone lock, it is one single main reason the coloring effect is drastically reduced in 2.6 (over 2.4) based kernels. -rohit From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH]: Free pages from local pcp lists under tight memory conditions From: Rohit Seth In-Reply-To: References: <20051122161000.A22430@unix-os.sc.intel.com> Content-Type: text/plain Date: Wed, 23 Nov 2005 11:46:34 -0800 Message-Id: <1132775194.25086.54.camel@akash.sc.intel.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: akpm@osdl.org, torvalds@osdl.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Wed, 2005-11-23 at 11:30 -0800, Christoph Lameter wrote: > On Tue, 22 Nov 2005, Rohit Seth wrote: > > > [PATCH]: This patch free pages (pcp->batch from each list at a time) from > > local pcp lists when a higher order allocation request is not able to > > get serviced from global free_list. > > Ummm.. One controversial idea: How about removing the complete pcp > subsystem? Last time we disabled pcps we saw that the effect > that it had was within noise ratio on AIM7. The lru lock taken without > pcp is in the local zone and thus rarely contended. Oh please stop. This per_cpu_pagelist is one great logic that has got added in allocator. Besides providing pages without the need to acquire the zone lock, it is one single main reason the coloring effect is drastically reduced in 2.6 (over 2.4) based kernels. -rohit -- 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