Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750984AbXBCSKJ (ORCPT ); Sat, 3 Feb 2007 13:10:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750973AbXBCSKJ (ORCPT ); Sat, 3 Feb 2007 13:10:09 -0500 Received: from omx2-ext.sgi.com ([192.48.171.19]:48214 "EHLO omx2.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750994AbXBCSKH (ORCPT ); Sat, 3 Feb 2007 13:10:07 -0500 Date: Sat, 3 Feb 2007 10:09:56 -0800 (PST) From: Christoph Lameter To: Arjan van de Ven cc: Andrew Morton , linux-kernel@vger.kernel.org, Nick Piggin , KAMEZAWA Hiroyuki , Rik van Riel Subject: Re: [RFC] Tracking mlocked pages and moving them off the LRU In-Reply-To: <1170525860.3073.1054.camel@laptopd505.fenrus.org> Message-ID: References: <20070203005316.eb0b4042.akpm@linux-foundation.org> <1170525860.3073.1054.camel@laptopd505.fenrus.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1317 Lines: 30 On Sat, 3 Feb 2007, Arjan van de Ven wrote: > it's simpler. You only move them off when you encounter them during a > scan. No walking early etc etc. Only do work when there is an actual > situation where you do scan. Yes but then you do not have an accurate count of MLOCKed pages. We will only have that count after reclaim has run and removed the pages from the LRU. That could take some time (or may never happen the way some people handle memory around here). > Well.. That's the point! Only IF there is a reclaim scan do you move > them out again. The fact that these pages are on the list isn't a > problem. The fact that you keep encountering them over and over again > during *scanning* is. So Andrews suggestion makes them go away in the > situations that actually matter I see... Okay that could be simple to address. > who cares though.. just do it lazy. The other issue that the patch should address is to allow the VM to have statistics that show the actual amount of MLOCKed pages. With the pure scanner based approach this would no longer work. - 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/