Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264074AbUDQXan (ORCPT ); Sat, 17 Apr 2004 19:30:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264075AbUDQXan (ORCPT ); Sat, 17 Apr 2004 19:30:43 -0400 Received: from florence.buici.com ([206.124.142.26]:28288 "HELO florence.buici.com") by vger.kernel.org with SMTP id S264074AbUDQXaj (ORCPT ); Sat, 17 Apr 2004 19:30:39 -0400 Date: Sat, 17 Apr 2004 16:30:37 -0700 From: Marc Singer To: Andrew Morton Cc: Marc Singer , wli@holomorphy.com, linux-kernel@vger.kernel.org Subject: Re: vmscan.c heuristic adjustment for smaller systems Message-ID: <20040417233037.GA15576@flea> References: <20040417193855.GP743@holomorphy.com> <20040417212958.GA8722@flea> <20040417162125.3296430a.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040417162125.3296430a.akpm@osdl.org> User-Agent: Mutt/1.5.5.1+cvs20040105i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1606 Lines: 44 On Sat, Apr 17, 2004 at 04:21:25PM -0700, Andrew Morton wrote: > Marc Singer wrote: > > > > I'd say that there is no statistically significant difference between > > these sets of times. However, after I've run the test program, I run > > the command "ls -l /proc" > > > > swappiness > > 60 (default) 0 > > ------------ -------- > > elapsed time(s) 18 1 > > 30 1 > > 33 1 > > How on earth can it take half a minute to list /proc? I've watched the vmscan code at work. The memory pressure is so high that it reclaims mapped pages zealously. The program's code pages are being evicted frequently. I would like to show a video of the ls -l /proc command. It's remarkable. The program pauses after displaying each line. > > This is the problem. Once RAM fills with IO buffers, the kernel's > > tendency to evict mapped pages ruins interactive performance. > > Is everything here on NFS, or are local filesystemms involved? (What does > "mount" say?) # mount rootfs on / type rootfs (rw) /dev/root on / type nfs (rw,v2,rsize=4096,wsize=4096,hard,udp,nolock,addr=192.168.8.1) proc on /proc type proc (rw) devpts on /dev/pts type devpts (rw) I've been wondering if the swappiness isn't a red herring. Is it reasonable that the distress value (in refill_inactive_zones ()) be 50? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/