From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by ug-out-1314.google.com with SMTP id c2so405057ugf for ; Thu, 09 Aug 2007 09:51:04 -0700 (PDT) Date: Thu, 9 Aug 2007 18:22:37 +0200 From: Diego Calleja Subject: Re: [PATCH 00/23] per device dirty throttling -v8 Message-Id: <20070809182237.b5afc4c7.diegocg@gmail.com> In-Reply-To: <46BB2C8E.2050205@redhat.com> References: <20070803123712.987126000@chello.nl> <20070804063217.GA25069@elte.hu> <20070804070737.GA940@elte.hu> <20070804103347.GA1956@elte.hu> <20070804163733.GA31001@elte.hu> <20070809062511.GA23435@capsaicin.mamane.lu> <46BB2C8E.2050205@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: owner-linux-mm@kvack.org Return-Path: To: Chuck Ebbert Cc: Lionel Elie Mamane , Ingo Molnar , Linus Torvalds , Peter Zijlstra , linux-mm@kvack.org, linux-kernel@vger.kernel.org, miklos@szeredi.hu, akpm@linux-foundation.org, neilb@suse.de, dgc@sgi.com, tomoki.sekiyama.qu@hitachi.com, nikita@clusterfs.com, trond.myklebust@fys.uio.no, yingcha@pimp.vs19.net List-ID: El Thu, 09 Aug 2007 11:02:38 -0400, Chuck Ebbert escribio: > NT maintains atimes by default, at least up to XP. You have to edit the > registry to turn them off, and it is a single global switch -- not per > mountpoint like Unix. > > And it makes a huge difference there, too. In windows Vista they've disabled atime updates by default. And XP maintains atimes, but it uses a trick to avoid the performance penalty we suffer in linux, similar to what Andi Kleen suggested: they keep atime updates in memory for one hour, and only sync to disk after that time - of course they also sync it if there's a oportunity to do it, like when updating mtime. -- 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