Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760392AbaGYV1R (ORCPT ); Fri, 25 Jul 2014 17:27:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:19867 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750732AbaGYV1Q (ORCPT ); Fri, 25 Jul 2014 17:27:16 -0400 Date: Fri, 25 Jul 2014 23:25:55 +0200 From: Jakub Jelinek To: Linus Torvalds Cc: Steven Rostedt , Alexei Starovoitov , Michel =?iso-8859-1?Q?D=E4nzer?= , Linux Kernel Mailing List , Debian GCC Maintainers , Debian Kernel Team Subject: Re: Random panic in load_balance() with 3.16-rc Message-ID: <20140725212555.GG2397@laptop.redhat.com> Reply-To: Jakub Jelinek References: <20140723190230.GH3935@laptop> <53D064C7.5050807@daenzer.net> <53D1B1EF.7030603@daenzer.net> <20140725035527.GA30108@pg-vmw-gw1> <20140725140237.GB32669@home.goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 25, 2014 at 01:01:11PM -0700, Linus Torvalds wrote: > For example, gcc will not create a small stack frame with "sub > $8,%rsp". No, what gcc does is to use a random "push" instruction. > Fair enough, but that really makes things much harder to see. Here's > an example: That is because for -Os, push is certainly shorter than sub $8,%rsp. If you want to test for this gcc bug in the kernel, supposedly one should just take the short testcase from the GCC PR, try to compile it and see if you e.g. get a -fcompare-debug -Os failure with the testcase. In that case, you could instead of giving up completely just -fno-var-tracking-assignments. Jakub -- 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/