From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH] 2.6.4-rc2-mm1: vm-split-active-lists Message-ID: From: Mark_H_Johnson@Raytheon.com Date: Fri, 12 Mar 2004 08:18:15 -0600 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, mfedyk@matchmail.com, m.c.p@wolk-project.de, owner-linux-mm@kvack.org, plate@gmx.tm List-ID: Nick Piggin wrote: >Andrew Morton wrote: >>That effect is to cause the whole world to be swapped out when people >>return to their machines in the morning. Once they're swapped back in the >>first thing they do it send bitchy emails to you know who. >> >>>>From a performance perspective it's the right thing to do, but nobody likes >>it. >> >> > >Yeah. I wonder if there is a way to be smarter about dropping these >used once pages without putting pressure on more permanent pages... >I guess all heuristics will fall down somewhere or other. Just a question, but I remember from VMS a long time ago that as part of the working set limits, the "free list" was used to keep pages that could be freely used but could be put back into the working set quite easily (a "fast" page fault). Could you keep track of the swapped pages in a similar manner so you don't have to go to disk to get these pages [or is this already being done]? You would pull them back from the free list and avoid the disk I/O in the morning. By the way - with 2.4.24 I see a similar behavior anyway [slow to get going in the morning]. I believe it is due to our nightly backup walking through the disks. If you could FIX the retention of sequentially read disk blocks from the various caches - that would help a lot more in my mind. --Mark H Johnson -- 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: aart@kvack.org