From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751610AbaHSUfX (ORCPT ); Tue, 19 Aug 2014 16:35:23 -0400 Received: from www17.your-server.de ([213.133.104.17]:60778 "EHLO www17.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750840AbaHSUfW (ORCPT ); Tue, 19 Aug 2014 16:35:22 -0400 Date: Tue, 19 Aug 2014 22:35:15 +0200 Subject: Re: [UML] 3.16 build without optimization fails From: Thomas Meyer To: Richard Weinberger Cc: linux@thorsten-knabe.de, Linux Kernel Mailing List , Valdis Kletnieks MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Message-Id: X-Authenticated-Sender: thomas@m3y3r.de Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id s7JKZS0L025496 Yes, it's still there. Am 19.08.2014 22:26 schrieb Richard Weinberger : > > On Tue, Aug 19, 2014 at 10:19 PM, Thomas Meyer wrote: > > Hi. > > > > Thanks for your answer. > > > > There goes my plan to better understand an UML kernel lock up by using a debugger... Everything gets optimised out with -O2 :-( > > Is it the filesystem/block lockup you saw some time ago? > Maybe Thorsten can give more details. > He sent me an patch off list a few days ago. > > > Can you give an example function that relies on this GCC feature? > > > > With kind regards > > Thomas > > > > Am 19.08.2014 22:06 schrieb Valdis.Kletnieks@vt.edu: > >> > >> On Tue, 19 Aug 2014 21:12:10 +0200, Thomas Meyer said: > >> > > Hi, > >> > > > >> > > the build with -O0 fails with: > >> > >> > > bug or feature? > >> > > > >> > > any ideas? > >> > >> Feature.  The kernel is *known* to not build with -O0, because that > >> disables *all* function inlining, and there's several functions that *have* > >> to be inlined in order to function properly (most notably, anything > >> that uses the gcc __builtin_return_address in a function that is expected > >> to be inlined). > > > > -- > Thanks, > //richard {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I