From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268668AbUHTTHD (ORCPT ); Fri, 20 Aug 2004 15:07:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268662AbUHTTEo (ORCPT ); Fri, 20 Aug 2004 15:04:44 -0400 Received: from omx3-ext.sgi.com ([192.48.171.20]:61589 "EHLO omx3.sgi.com") by vger.kernel.org with ESMTP id S268678AbUHTTC4 (ORCPT ); Fri, 20 Aug 2004 15:02:56 -0400 From: Jesse Barnes To: mita akinobu Subject: Re: [PATCH] shows Active/Inactive on per-node meminfo Date: Fri, 20 Aug 2004 15:01:31 -0400 User-Agent: KMail/1.6.2 Cc: linux-kernel@vger.kernel.org, Andrew Morton , Matthew Dobson References: <200408210302.25053.amgta@yacht.ocn.ne.jp> <200408201448.22566.jbarnes@engr.sgi.com> In-Reply-To: <200408201448.22566.jbarnes@engr.sgi.com> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200408201501.31542.jbarnes@engr.sgi.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Friday, August 20, 2004 2:48 pm, Jesse Barnes wrote: > On Friday, August 20, 2004 2:02 pm, mita akinobu wrote: > > + for (i = 0; i < MAX_NR_ZONES; i++) { > > + *active += zones[i].nr_active; > > + *inactive += zones[i].nr_inactive; > > + *free += zones[i].free_pages; > > + } > > +} > > + > > - *free += zone->free_pages; > > + for_each_pgdat(pgdat) { > > + unsigned long l, m, n; > > + __get_zone_counts(&l, &m, &n, pgdat); > > + *active += l; > > + *inactive += m; > > + *free += n; > > } > > Just FYI, loops like this are going to be very slow on a large machine. > Iterating over every node in the system involves a TLB miss on every > iteration along with an offnode reference and possibly cacheline demotion. ...but I see that you're just adding the info to the per-node meminfo files, so it should be ok as long as people access a node's meminfo file from a local cpu. /proc/meminfo will still hurt a lot though. I bring this up because I ran into it once. I created a file called /proc/discontig which printed out detailed per-node memory stats, one node per line. On a large system it would literally take several seconds to cat the file due to the overhead of looking at all the pages and zone structures. Jesse