From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 29 Jul 2007 18:53:17 +0100 From: Alan Cox Subject: Re: RFT: updatedb "morning after" problem [was: Re: -mm merge plans for 2.6.23] Message-ID: <20070729185317.5a5f1c30@the-village.bc.nu> In-Reply-To: <46ACCF7A.1080207@gmail.com> References: <9a8748490707231608h453eefffx68b9c391897aba70@mail.gmail.com> <46AC4B97.5050708@gmail.com> <20070729141215.08973d54@the-village.bc.nu> <46AC9F2C.8090601@gmail.com> <2c0942db0707290758p39fef2e8o68d67bec5c7ba6ab@mail.gmail.com> <46ACAB45.6080307@gmail.com> <2c0942db0707290820r2e31f40flb51a43846169a752@mail.gmail.com> <46ACB40C.2040908@gmail.com> <2c0942db0707290904n4356582dt91ab96b77db1e84e@mail.gmail.com> <46ACC76A.3080303@gmail.com> <2c0942db0707291019q14f309d0jab3bf083aa37d707@mail.gmail.com> <46ACCF7A.1080207@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Rene Herman Cc: Ray Lee , david@lang.hm, Daniel Hazelton , Mike Galbraith , Andrew Morton , Ingo Molnar , Frank Kingswood , Andi Kleen , Nick Piggin , Jesper Juhl , ck list , Paul Jackson , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: > > Is that generally the case on your systems? Every linux system I've > > run, regardless of RAM, has always pushed things out to swap. > > For me, it is generally the case yes. We are still discussing this in the > context of desktop machines and their problems with being slow as things > have been swapped out and generally I expect a desktop to have plenty of > swap which it's not regularly going to fillup significantly since then the > machine's unworkably slow as a desktop anyway. A simple log optimises writeout (which is latency critical) and can otherwise stall an enitre system. In a log you can also have multiple copies of the same page on disk easily, some stale - so you can write out chunks of data that are not all them removed from memory, just so you get them back more easily if you then do (and I guess you'd mark them accordingly) The second element is a cleaner - something to go around removing stuff from the log that is needed when the disks are idle - and also to repack data in nice linear chunks. So instead of using the empty disk time for page-in you use it for packing data and optimising future paging. -- 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: email@kvack.org