From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3D485775.14A8B483@zip.com.au> Date: Wed, 31 Jul 2002 14:32:37 -0700 From: Andrew Morton MIME-Version: 1.0 Subject: Re: throttling dirtiers References: <20020731171456.S10270@redhat.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: Benjamin LaHaise , William Lee Irwin III , "linux-mm@kvack.org" List-ID: Rik van Riel wrote: > > On Wed, 31 Jul 2002, Benjamin LaHaise wrote: > > On Wed, Jul 31, 2002 at 02:02:03PM -0700, Andrew Morton wrote: > > > But let's back off a bit. The problem is that a process > > > doing a large write() can penalise innocent processes which > > > want to allocate memory. > > > > > > How to fix that? > > > > First off, make it obvious where we block in the allocation path (pawning > > off all memory reaping to kswapd et al is an easy first step here). Then > > make allocators cycle through on a FIFO basis by using something like the > > page reservation patch I came up with a while ago. That'll give us an > > easy place to change scheduling behaviour. > > These ingredients are already in 2.4-rmap. It doesn't seem to work. The -ac kernel has weird stalls on storms of ext3 writeback. It's quite irritating, although probably not to do with the VM. The scheduler in the -ac kernel is also bad. Start a kernel build and things like X apps and gdb become hugely slow. 2.5 is like that too. I'll be going back to Marcelo. -- 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/