Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755105AbYHMRqx (ORCPT ); Wed, 13 Aug 2008 13:46:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752457AbYHMRqp (ORCPT ); Wed, 13 Aug 2008 13:46:45 -0400 Received: from hs-out-0708.google.com ([64.233.178.249]:20776 "EHLO hs-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752254AbYHMRqo (ORCPT ); Wed, 13 Aug 2008 13:46:44 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=wsys/dtL31rHvwWQtYiRGbRFo48BzHY8d6tha3BzFrORFxDPvMu9Kju9Of+TkwO0c6 P1lO9ajxTEnOmg+QOUIG1R4B7JDAvrOjAIs9P9ZV1xyTYzs2sORfZ4GeygfbZ8aa3I7X 6Qltt4pDqKFjOFZJYjM7PgmUWQ4TOa03qbe10= Message-ID: <86802c440808131046s4df84ba9va12d45897cf6affa@mail.gmail.com> Date: Wed, 13 Aug 2008 10:46:43 -0700 From: "Yinghai Lu" To: "Ingo Molnar" Subject: Re: 2.6.27rc1 cannot boot more than 8CPUs Cc: "Jeff Chua" , "David Miller" , "Linux Kernel" In-Reply-To: <20080813173940.GA32214@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080813141629.GD19397@elte.hu> <20080813173940.GA32214@elte.hu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1773 Lines: 48 On Wed, Aug 13, 2008 at 10:39 AM, Ingo Molnar wrote: > > * Jeff Chua wrote: > >> On Thu, Aug 14, 2008 at 1:10 AM, Jeff Chua wrote: >> > On Wed, Aug 13, 2008 at 10:16 PM, Ingo Molnar wrote: >> > >> >> btw., could you please check that v2.6.27-rc3 (or later) kernels boot >> >> fine (with about 8 cpus) even if you have genericarch/bigsmp disabled, >> >> and do not silently hang as it happened on your box before? >> > >> > With 16 CPUs, it still hangs, but now the console is showing the >> > errors as intended. >> > ... but it is supposed to hang? >> >> I tried with just CONFIG_NR_CPUS=8 and this time it booted, but stange >> thing is I only see 2 CPUs! To be more precise, it's without both >> CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP. >> >> And when I tried to enable the CPUs, it complained about: >> >> # cat cpu6/online >> 0 >> # echo 1 > cpu6/online >> More than 8 CPUs detected - skipping them. >> Use CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP. >> -bash: echo: write error: Input/output error >> >> Prior to the patch, the system booted with all 8 CPUs. that is new regression... >> >> Again, if I enable both CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP, >> I get all 16 CPUs. > > Yinghai, could the APIC ID enumeration be nonsequential and we skip CPUs > starting at the third one already? I think we should accept all CPUs > that are within our support range. will try to clear those bits on smp_sanity_check... YH -- 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/