From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754752AbZDYFYp (ORCPT ); Sat, 25 Apr 2009 01:24:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751884AbZDYFYh (ORCPT ); Sat, 25 Apr 2009 01:24:37 -0400 Received: from cantor.suse.de ([195.135.220.2]:47811 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751032AbZDYFYg (ORCPT ); Sat, 25 Apr 2009 01:24:36 -0400 Date: Sat, 25 Apr 2009 07:24:34 +0200 From: Nick Piggin To: Valdis.Kletnieks@vt.edu Cc: Andrew Morton , linux-kernel@vger.kernel.org, mm-commits@vger.kernel.org Subject: Re: mmotm 2009-04-24-18-14 uploaded - NVidia indigestion Message-ID: <20090425052434.GE10088@wotan.suse.de> References: <200904250133.n3P1XBJn006790@imap1.linux-foundation.org> <5622.1240628800@turing-police.cc.vt.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5622.1240628800@turing-police.cc.vt.edu> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 24, 2009 at 11:06:40PM -0400, Valdis.Kletnieks@vt.edu wrote: > On Fri, 24 Apr 2009 18:14:22 PDT, akpm@linux-foundation.org said: > > The mm-of-the-moment snapshot 2009-04-24-18-14 has been uploaded to > > > > http://userweb.kernel.org/~akpm/mmotm/ > > This jumped out and asked if I wanted SLQB as the default allocator (even > though I've had SLAB defined for ages). I said to myself "what the heck" > and accepted the change... Heh, it was a sneaky trick to get more testing before merging. Worked well :) > Tried to build the NVidia binary, and it choked during config on something > that will likely give a *lot* of programs indigestion. > > The test program: > > #include > #if defined(CONFIG_XEN) && defined(CONFIG_XEN_INTERFACE_VERSION) && !defined(__XEN_INTERFACE_VERSION__) > #define __XEN_INTERFACE_VERSION__ CONFIG_XEN_INTERFACE_VERSION > #endif > #include > #include > int main() { > if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)) { > return 0; > } else { > return 1; > } > } > > The command line: > > cc -D__KERNEL__ -DKBUILD_BASENAME="#conftest23112" -DKBUILD_MODNAME="#conftest23112" -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/4.4.0/include -I/lib/modules/2.6.30-rc3-mmotm0424/source/include/asm-x86_64/mach-default -I/lib/modules/2.6.30-rc3-mmotm0424/source/include/asm-x86/mach-default -I/lib/modules/2.6.30-rc3-mmotm0424/source/arch/x86/include/asm/mach-default -I/lib/modules/2.6.30-rc3-mmotm0424/build/include2 -I/lib/modules/2.6.30-rc3-mmotm0424/build/include -I/lib/modules/2.6.30-rc3-mmotm0424/source/include -I/lib/modules/2.6.30-rc3-mmotm0424/source/arch/x86/include -o conftest23112 conftest23112.c > > and the joy it got me: > > In file included from /lib/modules/2.6.30-rc3-mmotm0424/build/include/linux/slab.h:161, > from /lib/modules/2.6.30-rc3-mmotm0424/build/include/linux/percpu.h:5, > from /lib/modules/2.6.30-rc3-mmotm0424/build/include/linux/sched.h:76, > from /lib/modules/2.6.30-rc3-mmotm0424/build/include/linux/utsname.h:35, > from conftest2465.c:6: > /lib/modules/2.6.30-rc3-mmotm0424/build/include/linux/slqb_def.h: In function ???kmalloc_slab???: > /lib/modules/2.6.30-rc3-mmotm0424/build/include/linux/slqb_def.h:240: error: size of array ???type name??? is negative > > Why does utsname.h care about SLAB versus SLUB? (Looks to me like somebody > forgot to add a #include to slqb_def.h for all the headers it needed, and > it choked. Interestingly enough, line 240 reads: > > BUILD_BUG_ON(!__builtin_constant_p(size)); > > but I didn't think this was the way BUILD_BUG_ON worked? Yeah BUILD_BUG_ON does work like that. I can't for the life of me understand why it triggered though. Is anything in your external code calling kmalloc_slab directly? What's the preprocessor output look like?