From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935686AbWLAHvW (ORCPT ); Fri, 1 Dec 2006 02:51:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S935687AbWLAHvW (ORCPT ); Fri, 1 Dec 2006 02:51:22 -0500 Received: from omx1-ext.sgi.com ([192.48.179.11]:57293 "EHLO omx1.sgi.com") by vger.kernel.org with ESMTP id S935686AbWLAHvV (ORCPT ); Fri, 1 Dec 2006 02:51:21 -0500 Date: Thu, 30 Nov 2006 23:51:17 -0800 From: Paul Jackson To: Christoph Lameter Cc: akpm@osdl.org, linux-kernel@vger.kernel.org Subject: Re: Avoid allocating during interleave from almost full nodes Message-Id: <20061130235117.018c3c70.pj@sgi.com> In-Reply-To: References: <20061103134633.a815c7b3.akpm@osdl.org> <20061103143145.85a9c63f.akpm@osdl.org> <20061103172605.e646352a.pj@sgi.com> <20061103174206.53f2c49e.akpm@osdl.org> <20061104025128.ca3c9859.pj@sgi.com> Organization: SGI X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.3; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org A month ago, Christoph replied to pj: > > On Sat, 4 Nov 2006, Paul Jackson wrote: > > > Do you know of any existing counters that we could use like this? > > > > Adding a system wide count of pages allocated or scanned, just for > > these fullnode hint caches, bothers me. > > There are already such counters. PGALLOC_* and PGSCAN_*. See > include/linux/vmstat.h These counters depend on CONFIG_VM_EVENT_COUNTERS. The Kconfig comment for CONFIG_VM_EVENT_COUNTERS states: VM event counters are only needed to for event counts to be shown. They have no function for the kernel itself. This option allows the disabling of the VM event counters. /proc/vmstat will only show page counts. (By the way - note the "needed to for event" phrasing error.) The header file, include/linux/vmstat.h, for these counters states: /* * Light weight per cpu counter implementation. * * Counters should only be incremented and no critical kernel component * should rely on the counter values. Both these clearly state that I should not use these counters for real kernel functions. If that is so, I should find some other "time base" for the zonelist caching. If that is not so, then these comments need updating. Anybody have any idea which is the case? -- I won't rest till it's the best ... Programmer, Linux Scalability Paul Jackson 1.925.600.0401