Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932959AbaGWSYQ (ORCPT ); Wed, 23 Jul 2014 14:24:16 -0400 Received: from casper.infradead.org ([85.118.1.10]:38219 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932797AbaGWSYP (ORCPT ); Wed, 23 Jul 2014 14:24:15 -0400 Date: Wed, 23 Jul 2014 20:24:13 +0200 From: Peter Zijlstra To: Linus Torvalds Cc: Dietmar Eggemann , Michel =?iso-8859-1?Q?D=E4nzer?= , Ingo Molnar , Linux Kernel Mailing List Subject: Re: Random panic in load_balance() with 3.16-rc Message-ID: <20140723182413.GC3935@laptop> References: <53CF80EE.5050702@daenzer.net> <53CF844A.5050106@arm.com> <20140723111110.GT3935@laptop> <20140723113021.GP12054@laptop.lan> <20140723142454.GQ12054@laptop.lan> <20140723155526.GW3935@laptop> <20140723170324.GZ3935@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 23, 2014 at 10:12:35AM -0700, Linus Torvalds wrote: > On Wed, Jul 23, 2014 at 10:03 AM, Peter Zijlstra wrote: > > On Wed, Jul 23, 2014 at 09:54:23AM -0700, Linus Torvalds wrote: > >> > >> And I wonder if I have a clue. Look, load_balance_mask is a > >> "cpumask_var_t", but I don't see a "alloc_cpumask_var()" for it. > >> That's broken with CONFIG_CPUMASK_OFFSTACK. > > > > kernel/sched/core.c:sched_init() > > > > plays horrible allocation tricks.. > > No it does not. It allocates a cpumask. Nothing more. If you think it > allocates a "cpumask_var()", you are wrong. I was merely saying 'something' got allocated, but yes I'll agree its not a cpumask_var_t thingy. > I agree that the code is an unreadable mess, but that's what > "cpumask_size()" is: the minimum required size of the bitmask in a > cpumask. Latest patch cures at least this part of that mess. -- 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/