From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sat, 4 Aug 2007 18:37:33 +0200 From: Ingo Molnar Subject: Re: [PATCH 00/23] per device dirty throttling -v8 Message-ID: <20070804163733.GA31001@elte.hu> References: <20070803123712.987126000@chello.nl> <20070804063217.GA25069@elte.hu> <20070804070737.GA940@elte.hu> <20070804103347.GA1956@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org Return-Path: To: Linus Torvalds Cc: 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, yingchao.zhou@gmail.com, richard@rsk.demon.co.uk List-ID: * Linus Torvalds wrote: > > hm, it turns out that it's due to vim doing an occasional fsync not > > only on writeout, but during normal use too. "set nofsync" in the > > .vimrc solves this problem. > > Yes, that's independent. The fact is, ext3 *sucks* at fsync. I hate > hate hate it. It's totally unusable, imnsho. yeah, it's really ugly. But otherwise i've got no real complaint about ext3 - with the obligatory qualification that "noatime,nodiratime" in /etc/fstab is a must. This speeds up things very visibly - especially when lots of files are accessed. It's kind of weird that every Linux desktop and server is hurt by a noticeable IO performance slowdown due to the constant atime updates, while there's just two real users of it: tmpwatch [which can be configured to use ctime so it's not a big issue] and some backup tools. (Ok, and mail-notify too i guess.) Out of tens of thousands of applications. So for most file workloads we give Windows a 20%-30% performance edge, for almost nothing. (for RAM-starved kernel builds the performance difference between atime and noatime+nodiratime setups is more on the order of 40%) Ingo -- 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