From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261295AbVFMA36 (ORCPT ); Sun, 12 Jun 2005 20:29:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261297AbVFMA36 (ORCPT ); Sun, 12 Jun 2005 20:29:58 -0400 Received: from wproxy.gmail.com ([64.233.184.205]:63026 "EHLO wproxy.gmail.com") by vger.kernel.org with ESMTP id S261295AbVFMA3l convert rfc822-to-8bit (ORCPT ); Sun, 12 Jun 2005 20:29:41 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=dPLFD7g8/g2hWL996TX9JY4gOe5dG6uA0i9nnx8BblxIHwxnIauuA25NLB+7M9DzGD1FD54hH6l2+eG/amV/+XgkUElrgnyXaASlpuXurujNQ+N+KMeS8H3PrydLmbLUUsLShMZdRlPMqHW3zJ6bWlrnHoN30lzv4VGFmU704Hg= Message-ID: Date: Mon, 13 Jun 2005 03:29:39 +0300 From: Kemal Hadimli Reply-To: Kemal Hadimli To: linux-kernel@vger.kernel.org Subject: poor performance with HIGHMEM? Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello, Recently i'm having performance problems with my P4-HT highmem system. Tried two motherboards, different RAM chips (4x1gig and 4x512mb), but the problem remains unchanged. In my case i found that the 2.4 (2.4.26 and 2.4.30) series are faster than the 2.6 (tried with 2.6.0, 2.6.6, 2.6.7, 2.6.7-bk4, 2.6.10, and the recent 2.6.11.12) series. But the performance is still very poor compared to what i get with lowmem. The performance gets much better if I force 768megs of ram (passing the "mem=768" parameter) so it looks like the problem is highmem. The box normally has 4 gigabytes of ram (4 sticks of 1 Gig, PC3200) and handles mostly mySQL+Apache2+PHP4. Kernel parameters: CONFIG_HIGHMEM64G=y (I am told that CONFIG_HIGHMEM4G would lead to bad performance. there's no other reason i'm using 64G and not 4G) whole configs are accessible at: http://www.ehore.com/kernel/config-2.4.30 http://www.ehore.com/kernel/config-2.6.11.12 The motherboards I tried and the /proc/mtrr and E820 output: ASUS P4P800-SE reg00: base=0x00000000 ( 0MB), size=2048MB: write-back, count=1 reg01: base=0x80000000 (2048MB), size=1024MB: write-back, count=1 reg02: base=0xc0000000 (3072MB), size= 512MB: write-back, count=1 reg03: base=0xe0000000 (3584MB), size= 256MB: write-back, count=1 reg04: base=0xf0000000 (3840MB), size= 128MB: write-back, count=1 reg05: base=0xf8000000 (3968MB), size= 64MB: write-back, count=1 BIOS-e820: 0000000000000000 - 000000000009fc00 (usable) BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved) BIOS-e820: 00000000000e8000 - 0000000000100000 (reserved) BIOS-e820: 0000000000100000 - 00000000fd430000 (usable) BIOS-e820: 00000000fd430000 - 00000000fd440000 (ACPI data) BIOS-e820: 00000000fd440000 - 00000000fd4f0000 (ACPI NVS) BIOS-e820: 00000000fd4f0000 - 00000000fd500000 (reserved) BIOS-e820: 00000000ffb80000 - 0000000100000000 (reserved) Gigabyte GA-8IG1000-G (onboard vga, configured as 1mb) reg00: base=0x00000000 ( 0MB), size=2048MB: write-back, count=1 reg01: base=0x80000000 (2048MB), size=1024MB: write-back, count=1 reg02: base=0xc0000000 (3072MB), size= 512MB: write-back, count=1 reg03: base=0xe0000000 (3584MB), size= 128MB: write-back, count=1 reg04: base=0xe7f00000 (3711MB), size= 1MB: uncachable, count=1 BIOS-e820: 0000000000000000 - 000000000009f800 (usable) BIOS-e820: 000000000009f800 - 00000000000a0000 (reserved) BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved) BIOS-e820: 0000000000100000 - 00000000e7ef0000 (usable) BIOS-e820: 00000000e7ef0000 - 00000000e7ef3000 (ACPI NVS) BIOS-e820: 00000000e7ef3000 - 00000000e7f00000 (ACPI data) BIOS-e820: 00000000fec00000 - 0000000100000000 (reserved) So, what are your .config/patch/version recommendations for a highmem system like this one? Hoping to get some replies, and thanks for your time :) -- Kemal