From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751767AbaJOQFl (ORCPT ); Wed, 15 Oct 2014 12:05:41 -0400 Received: from terminus.zytor.com ([198.137.202.10]:57311 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751322AbaJOQFk (ORCPT ); Wed, 15 Oct 2014 12:05:40 -0400 Message-ID: <543E9B4B.9040608@zytor.com> Date: Wed, 15 Oct 2014 09:05:31 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1 MIME-Version: 1.0 To: Prarit Bhargava CC: linux-kernel@vger.kernel.org, x86@kernel.org Subject: Re: Lockdep warning with init_espfix_ap() References: <5436AB4A.1080900@redhat.com> <543E994F.5030406@zytor.com> <543E9ACE.7050009@redhat.com> In-Reply-To: <543E9ACE.7050009@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/15/2014 09:03 AM, Prarit Bhargava wrote: >> >> It is kind of a messy situation, because this code needs to allocate >> memory but is run before the secondary CPU is fully up. As such, it is >> a false positive, at least in some ways. > > Interesting -- FWIW, I can reproduce this 100% of the time on _one_ system. It > isn't a big deal and likely just worth noting at this point. I *always* see it > when bringing up CPU 64 (of 128). > ... because that is the first CPU which needs to allocate memory. -hpa