Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264094AbUDRB7X (ORCPT ); Sat, 17 Apr 2004 21:59:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264100AbUDRB7X (ORCPT ); Sat, 17 Apr 2004 21:59:23 -0400 Received: from holomorphy.com ([207.189.100.168]:27533 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S264094AbUDRB7V (ORCPT ); Sat, 17 Apr 2004 21:59:21 -0400 Date: Sat, 17 Apr 2004 18:59:18 -0700 From: William Lee Irwin III To: Andrew Morton Cc: Marc Singer , linux-kernel@vger.kernel.org Subject: Re: vmscan.c heuristic adjustment for smaller systems Message-ID: <20040418015918.GU743@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Andrew Morton , Marc Singer , linux-kernel@vger.kernel.org References: <20040417193855.GP743@holomorphy.com> <20040417212958.GA8722@flea> <20040417162125.3296430a.akpm@osdl.org> <20040417233037.GA15576@flea> <20040417165151.24b1fed5.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040417165151.24b1fed5.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: 1928 Lines: 45 Marc Singer wrote: >> 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. On Sat, Apr 17, 2004 at 04:51:51PM -0700, Andrew Morton wrote: > Which tends to imply that the VM is not reclaiming any of that nfs-backed > pagecache. The observation that prompted the max() vs. addition was: On Sat, Apr 17, 2004 at 10:57:24AM -0700, Marc Singer wrote: > I don't think that's the whole story. I printed distress, > mapped_ratio, and swappiness when vmscan starts trying to reclaim > mapped pages. > reclaim_mapped: distress 50 mapped_ratio 0 swappiness 60 > 50 + 60 > 100 > So, part of the problem is swappiness. I could set that value to 25, > for example, to stop the machine from swapping. > I'd be fine stopping here, except for you comment about what > swappiness means. In my case, nearly none of memory is mapped. It is > zone priority which has dropped to 1 that is precipitating the > eviction. Is this what you expect and want? Marc Singer wrote: >> 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? On Sat, Apr 17, 2004 at 04:51:51PM -0700, Andrew Morton wrote: > I'd assume that setting swappiness to zero simply means that you still have > all of your libc in pagecache when running ls. > What happens if you do the big file copy, then run `sync', then do the ls? > Have you experimented with the NFS mount options? v2? UDP? I wonder if the ptep_test_and_clear_young() TLB flushing is related. -- wli - 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/