From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sat, 4 Aug 2007 09:15:24 -0700 (PDT) From: Linus Torvalds Subject: Re: [PATCH 00/23] per device dirty throttling -v8 In-Reply-To: <20070804070737.GA940@elte.hu> Message-ID: References: <20070803123712.987126000@chello.nl> <20070804063217.GA25069@elte.hu> <20070804070737.GA940@elte.hu> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: Ingo Molnar 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: On Sat, 4 Aug 2007, Ingo Molnar wrote: > > i forgot this entry: > > " We recently upgraded our office to gigabit Ethernet and got some big > AMD64 / 3ware boxes for file and vmware servers... only to find them > almost useless under any kind of real load. I've built some patched > 2.6.21.6 kernels (using the bdi throttling patch you mentioned) to > see if our various Debian Etch boxes run better. So far my testing > shows a *great* improvement over the stock Debian 2.6.18 kernel on > our configurations. " Well, quite frankly, there are other changes between 2.6.18 and 2.6.21 that are more likely to be a big deal than Peter's patches. No offense to Peter, but we also cut the default dirty percentage by a factor of four in that timeframe, and that made a *huge* difference for some setups (and admittedly not so much on others ;) > and bdi has been in -mm in the past i think, so we also know (to a > certain degree) that it does not hurt those workloads that are fine > either. Hey, I'm not complaining. I think the code looks fine. I just want to make sure that it actually helps. > [ my personal interest in this is the following regression: every time i > start a large kernel build with DEBUG_INFO on a quad-core 4GB RAM box, > i get up to 30 seconds complete pauses in Vim (and most other tasks), > during plain editing of the source code. (which happens when Vim tries > to write() to its swap/undo-file.) ] So do the patches really end up helping your case? Or is this just why you're following it, and hoping they'll eventually do so? Linus -- 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