Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754628AbXI1RqV (ORCPT ); Fri, 28 Sep 2007 13:46:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751907AbXI1RqN (ORCPT ); Fri, 28 Sep 2007 13:46:13 -0400 Received: from mx1.redhat.com ([66.187.233.31]:47377 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751598AbXI1RqM (ORCPT ); Fri, 28 Sep 2007 13:46:12 -0400 Message-ID: <46FD3DE1.9000807@redhat.com> Date: Fri, 28 Sep 2007 13:46:09 -0400 From: Chuck Ebbert Organization: Red Hat User-Agent: Thunderbird 1.5.0.12 (X11/20070719) MIME-Version: 1.0 To: Sergey Popov CC: linux-kernel@vger.kernel.org Subject: Re: General slowness with using 64Gb HIGHMEM option on 32-bit kernel References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1662 Lines: 34 On 09/28/2007 01:15 PM, Sergey Popov wrote: > Short description: after recompiling 32-bit kernel with 64Gb highmem > support and rebooting into it, OS started working very much slower > then before. > > Specifications: Intel Core 2 Duo E6600@2,4Ghz on Intel i965Q-based > motherboard. 6Gb of DDR2 RAM, 2x1Gb+2x2Gb, dual-channel. > Vector Linux 5.8 (Slackware Linux 11-based), 2.6.20.3 kernel. > > Long description: after recompiling 32-bit 2.6.20.3 kernel with 64Gb > highmem option and rebooting into it, booting process froze on udevd. > After booting up from CD and disabling rc.udev, system started, but > it's work after rc.M script sarted was 5-10 times slower then usual. > top showed, that processes are taking much more CPU% time then usual. > I tried downloading the newest stable kernel - 2.6.22.9 - hoping, that > it would solve the problem. I downloaded it, booted from CD, and > compiled it with 64Gb highmem support. I felt some speed improvement, > but if on 2.6.20.3 machine performed like P166, now it is working like > P2-350. > I've found a similar problem, described on lkml - > http://lkml.org/lkml/2007/5/30/5 . But, unfortunately, it is x86_64 > related and contains no clues for me. > > Moving to 64-bit distro is rather unpleasant - as there is an option > in 32-bit kernel, it should work ;) . > > What tests should I run to help investigate this problem? Boot with option "mem=3900M". - 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/