From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268328AbUHLCYA (ORCPT ); Wed, 11 Aug 2004 22:24:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268353AbUHLCYA (ORCPT ); Wed, 11 Aug 2004 22:24:00 -0400 Received: from out008pub.verizon.net ([206.46.170.108]:9875 "EHLO out008.verizon.net") by vger.kernel.org with ESMTP id S268328AbUHLCXw (ORCPT ); Wed, 11 Aug 2004 22:23:52 -0400 From: Gene Heskett Reply-To: gene.heskett@verizon.net Organization: Organization: None, detectable by casual observers To: linux-kernel@vger.kernel.org Subject: Re: Possible dcache BUG Date: Wed, 11 Aug 2004 22:23:50 -0400 User-Agent: KMail/1.6.82 Cc: Nick Piggin , Linus Torvalds , "Udo A. Steinberg" , Andrew Morton , viro@parcelfarce.linux.theplanet.co.uk References: <200408111037.56062.gene.heskett@verizon.net> <411AC750.3040809@yahoo.com.au> In-Reply-To: <411AC750.3040809@yahoo.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200408112223.50438.gene.heskett@verizon.net> X-Authentication-Info: Submitted using SMTP AUTH at out008.verizon.net from [151.205.10.83] at Wed, 11 Aug 2004 21:23:51 -0500 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 11 August 2004 21:26, Nick Piggin wrote: >Gene Heskett wrote: >>On Wednesday 11 August 2004 01:15, Linus Torvalds wrote: >>>On Tue, 10 Aug 2004, Linus Torvalds wrote: >>>>So I suspect it's a balancing issue. Possibly just the slight >>>>change in slab balancing to fix the highmem problems. Maybe we >>>>shrink slab _too_ aggressively or something. >>> >>>Udo, that's a simple thing to check. If it's the slab balancing >>>changes, then you should be able to test it with just a >>> >>> bk cset -x1.1830.4.3 >>> >>>if you have the current BK and are a BK user, or by just revertign >>>the patch here ("patch -R -p1" from inside your linux source tree) >>>if you're not a BK user.. >>> >>> Linus >> >>With the previously attached patch reverted, a fresh kernel builds >> in: real 7m18.296s >>user 5m49.385s >>sys 0m31.760s >>which is a marked improvement, but still about 1m30 or so slow. > >This could easily be from too much slab pressure. How much memory do > you have? 1 Gb in 2 512Mb sticks of DDR400 ram which signs on in the bios as dual channel. The sticks are in the first and third slots as recommended by the mobo docs. >Have you got highmem turned on? Yes >The new slab pressure calculation is an improvement in that it won't > let slab >get out of control and cause OOMs, however it can shrink the slab > too much. If you regularly need ZONE_DMA pages, for example. AFAIKS > there isn't much you >can do about this except go to per-zone slab LRUs. And how would an otherwise clueless user like me determine that? >That said, your stability problems should be resolved first. If they > are fixed, Which as yet is an unknown, Nick. Uptime now at 22:15:14 up 12:30, 5 users, load average: 1.03, 1.11, 1.05 >and you would like to help track down the slowdown, run the kernel >compile about >3 times each with and without the patch, and save cat /proc/vmstat >before and >after each compile. Try to keep all else constant. I'll try that if I get to a 30+ hour uptime. >Thanks >Nick -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) 99.24% setiathome rank, not too shabby for a WV hillbilly Yahoo.com attorneys please note, additions to this message by Gene Heskett are: Copyright 2004 by Maurice Eugene Heskett, all rights reserved.