From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755155AbXLVU1u (ORCPT ); Sat, 22 Dec 2007 15:27:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753354AbXLVU1m (ORCPT ); Sat, 22 Dec 2007 15:27:42 -0500 Received: from e31.co.us.ibm.com ([32.97.110.149]:38579 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753029AbXLVU1m (ORCPT ); Sat, 22 Dec 2007 15:27:42 -0500 Message-ID: <476D7334.4010301@linux.vnet.ibm.com> Date: Sun, 23 Dec 2007 01:57:32 +0530 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com Organization: IBM User-Agent: Thunderbird 2.0.0.6 (X11/20071022) MIME-Version: 1.0 To: Rik van Riel CC: linux-mm@kvack.org, linux-kernel@vger.kernel.org, lee.shermerhorn@hp.com Subject: Re: [patch 00/20] VM pageout scalability improvements References: <20071218211539.250334036@redhat.com> In-Reply-To: <20071218211539.250334036@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Rik van Riel wrote: > On large memory systems, the VM can spend way too much time scanning > through pages that it cannot (or should not) evict from memory. Not > only does it use up CPU time, but it also provokes lock contention > and can leave large systems under memory presure in a catatonic state. > Hi, Rik, I remember you mentioning that by large memory systems you mean systems with at-least 128GB, does this definition still hold? > This patch series improves VM scalability by: > > 1) making the locking a little more scalable > > 2) putting filesystem backed, swap backed and non-reclaimable pages > onto their own LRUs, so the system only scans the pages that it > can/should evict from memory > > 3) switching to SEQ replacement for the anonymous LRUs, so the > number of pages that need to be scanned when the system > starts swapping is bound to a reasonable number > > The noreclaim patches come verbatim from Lee Schermerhorn and > Nick Piggin. I have not taken a detailed look at them yet and > all I have done is fix the rejects against the latest -mm kernel. > Is there a consolidate patch available, it makes it easier to test. > I am posting this series now because I would like to get more > feedback, while I am studying and improving the noreclaim patches > myself. > What kind of tests show the problem? I'll try and review and test the code. -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL