From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262695AbTLCX6o (ORCPT ); Wed, 3 Dec 2003 18:58:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262730AbTLCX6n (ORCPT ); Wed, 3 Dec 2003 18:58:43 -0500 Received: from holomorphy.com ([199.26.172.102]:6863 "EHLO holomorphy") by vger.kernel.org with ESMTP id S262695AbTLCX6m (ORCPT ); Wed, 3 Dec 2003 18:58:42 -0500 Date: Wed, 3 Dec 2003 15:58:37 -0800 From: William Lee Irwin III To: Ethan Weinstein Cc: linux-kernel@vger.kernel.org Subject: Re: HT apparently not detected properly on 2.4.23 Message-ID: <20031203235837.GW8039@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Ethan Weinstein , linux-kernel@vger.kernel.org References: <3FCE2F8E.90104@stinkfoot.org> <20031203224023.GV8039@holomorphy.com> <3FCE74B0.9010506@stinkfoot.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3FCE74B0.9010506@stinkfoot.org> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org William Lee Irwin III wrote: >>You probably have sparse physical APIC ID's. On Wed, Dec 03, 2003 at 06:41:36PM -0500, Ethan Weinstein wrote: > Ok, setting CONFIG_NR_CPUS=8 does indeed solve the HT issue, looks like > it was the numbering scheme: It's easy to fix this; just terminate the loop when the count of cpus kicked hits NR_CPUS or the bit would overflow the map instead of the bit hitting NR_CPUS. Compare smpboot.c in 2.4 vs. 2.6. No need for the extra CONFIG_NR_CPUS bloat. On Wed, Dec 03, 2003 at 06:41:36PM -0500, Ethan Weinstein wrote: > But we're still only interrupting on CPU0 with this kernel. That's P-IV retardation. Not really fixable, but irqbalance daemons etc. can help mitigate the severity of the erratum. I'm not sure if 2.4 has the interfaces for the userspace solutions to work or the kernel solutions either. -- wli