From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267609AbUHPNXq (ORCPT ); Mon, 16 Aug 2004 09:23:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267622AbUHPNXq (ORCPT ); Mon, 16 Aug 2004 09:23:46 -0400 Received: from 64.89.71.154.nw.nuvox.net ([64.89.71.154]:5249 "EHLO gate.apago.com") by vger.kernel.org with ESMTP id S267609AbUHPNXm (ORCPT ); Mon, 16 Aug 2004 09:23:42 -0400 SMTP-Relay: dogwood.freil.com Message-Id: <200408161323.i7GDNeod020199@dogwood.freil.com> X-Mailer: exmh version 2.0.2 2/24/98 To: linux-kernel@vger.kernel.org Subject: Re: Serious Kernel slowdown with HIMEM (4Gig) in 2.6.7 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 16 Aug 2004 09:23:40 -0400 From: "Lawrence E. Freil" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Iteresting idea, here is the /proc/mtrr output: reg00: base=0x00000000 ( 0MB), size= 512MB: write-back, count=1 reg01: base=0x20000000 ( 512MB), size= 256MB: write-back, count=1 reg02: base=0x30000000 ( 768MB), size= 128MB: write-back, count=1 reg03: base=0x38000000 ( 896MB), size= 64MB: write-back, count=1 reg04: base=0x3c000000 ( 960MB), size= 32MB: write-back, count=1 reg05: base=0x3e000000 ( 992MB), size= 16MB: write-back, count=1 reg06: base=0xf0000000 (3840MB), size= 2MB: write-combining, count=1 The memory in question is the block from 896 to 1Gig. Looks pretty normal. At this point I need to recompile "ls" with full profiling and time it with and without extended memory. I have a suspicion that it is related to "mmap" on data in a high memory buffer. It does not effect actual file read/write. Performance on that is pretty much the same. >On Sat, Aug 14, 2004 at 12:43:11PM -0400, Lawrence E. Freil wrote: >> Though there is a consistant sys component that is slightly higher. I ran >> profiles three times for "fast" and three times for "slow". Here they are > >Try cat /proc/mtrr. I bet your system isn't marking some of its RAM >cachable in the MTRRs. > > -ben -- Lawrence Freil Email:lef@freil.com 1768 Old Country Place Phone:(770) 667-9274 Woodstock, GA 30188