From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752371AbZIZSKv (ORCPT ); Sat, 26 Sep 2009 14:10:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751737AbZIZSKu (ORCPT ); Sat, 26 Sep 2009 14:10:50 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:39566 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751602AbZIZSKt (ORCPT ); Sat, 26 Sep 2009 14:10:49 -0400 Date: Sat, 26 Sep 2009 20:10:37 +0200 From: Ingo Molnar To: Linus Torvalds Cc: Andi Kleen , fengguang.wu@intel.com, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, "H. Peter Anvin" , Thomas Gleixner , Peter Zijlstra Subject: Re: [PATCH] x86: Fix hwpoison code related build failure on 32-bit NUMAQ Message-ID: <20090926181037.GA4666@elte.hu> References: <20090916125116.GA12751@basil.fritz.box> <20090926141352.GA26117@elte.hu> <20090926151740.GN30185@one.firstfloor.org> <20090926173522.GA22723@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Linus Torvalds wrote: > On Sat, 26 Sep 2009, Ingo Molnar wrote: > > > > > > +config X86_SUPPORTS_MEMORY_FAILURE > > > + bool > > > + depends on !X86_NUMAQ > > > + select ARCH_SUPPORTS_MEMORY_FAILURE > > > + default y > > > > Thanks Linus, this patch fixed the NUMAQ build problem. > > I think it's slightly buggy still. > > I think the X86_SUPPORTS_MEMORY_FAILURE thing should also have a > > depends on X86_MCE > > line, because we still depend on MCE. Yeah. ( Note, it should not necessarily depend on it: while the only hw mechanism that calls memory_failure() is indeed MCE, the act of having a memory-failures subsystem does not depend on the presence of an x86 MCE subsystem. There's for example the injection debug-code which allows the injection of memory_failure() calls. That should work fine without having MCE build in as well. But that is a separate change. ) > And as you found out, there's also the sparsemem thing. > > Don't make it one huge ugly thing, just split out the requirements like > > depends on X86_MCE > depends on !X86_NUMAQ > depends on X86_64 || !SPARSEMEM > > because I think the requirements are fairly independent, and it makes > it easier to read (you could even comment each line on why _that_ > particular issue needs to disable X86_SUPPORTS_MEMORY_FAILURE) Good idea, have done that too. > But yeah, with that, and some testing, please add my sign-off (or > acked-by, if you end up changing the patch so much that it has little > to do with my original one) It's still mostly your patch so i've added your SOB, thanks. Below is the updated patch. btw., i think mm/memory-failure.c needs similar cleanups to ARCH_SUPPORTS_MEMORY_FAILURE. Right now it is full of x86 details, not sure that is right. 'MCE' for example is an x86 expression and goes way beyond just memory errors - it stands for 'Machine Check Exception' and covers IO/bus errors, etc. We even put 'MCE' into new ABI details in include/asm-generic/siginfo.h: /* hardware memory error consumed on a machine check: action required */ #define BUS_MCEERR_AR (__SI_FAULT|4) /* hardware memory error detected in process but not consumed: action optional*/ #define BUS_MCEERR_AO (__SI_FAULT|5) #define NSIGBUS 5 That should be fixed to be something like: BUS_MEMERR_MANDATORY BUS_MEMERR_OPTIONAL before such a kernel is released, IMHO. In mm/memory-failure.c i find the 'ao' / 'ar' abbreviations rather unreadable as well - they are totally meaningless (to me at least), even if i know the code. Same goes for the me_*() prefixes. Also, 'struct to_kill' .... Ingo