Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753797AbXJ0GGU (ORCPT ); Sat, 27 Oct 2007 02:06:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751536AbXJ0GGJ (ORCPT ); Sat, 27 Oct 2007 02:06:09 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.144]:38756 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751506AbXJ0GGI (ORCPT ); Sat, 27 Oct 2007 02:06:08 -0400 Message-ID: <4722D516.8020902@linux.vnet.ibm.com> Date: Sat, 27 Oct 2007 11:35:10 +0530 From: Balbir Singh Reply-To: balbir@linux.vnet.ibm.com Organization: IBM User-Agent: Thunderbird 1.5.0.13 (X11/20070824) MIME-Version: 1.0 To: Al Viro CC: Jeff Dike , Thomas Gleixner , Ingo Molnar , Linux Kernel Mailing List Subject: Re: [x86 patch] Fix UML signal.h build errors References: <20071025130022.8720.77346.sendpatchset@balbir-laptop> <20071025150541.GB5968@c2.user-mode-linux.org> <4720B6E8.4090003@linux.vnet.ibm.com> <20071027031309.GI8181@ftp.linux.org.uk> In-Reply-To: <20071027031309.GI8181@ftp.linux.org.uk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1712 Lines: 51 Al Viro wrote: > On Thu, Oct 25, 2007 at 09:01:52PM +0530, Balbir Singh wrote: > >> Thats nice, I wonder why I missed them searching on lkml in my gmail box >> :( >> >> Is __arch_um__ the right thing to do or BITS_PER_LONG == 32? I prefer >> BITS_PER_LONG == 32 over #if defined(__i386__) || defined(__arch__um__). >> I guess its a matter of personal preference. > > Huh? > > a) we really shouldn't mess with compiler defines (i.e. we should not > undef __i386__ or __x86_64__) > I agree > b) I'd rather have __arch_um__ mentioned explicitly in 3 places where > we do care about difference between i386 and uml/i386 than have certain > to be forgotten rules for places like include/asm-x86 > > c) if you look at those places, you'll see > * drivers/char/mem.c::uncached_access(). Really per-architecture > and I wonder if it might be include/asm-* fodder... > * kernel/signal.c debugging printks. Should die or be sanitized, IMO. > * raid6 algorithms. Hell knows - immediate reason why we don't do > those on uml is the lack of kernel_fpu_begin()/kernel_fpu_end() (and > boot_cpu_has(), but that's easier to add). Do we care to implement that > stuff? > I suspect that list might grow and anybody writing i386 or x86_64 code will need to double check if the code will work under __arch_um__. Probably worth documenting somewhere. > That's _all_. Nothing else has to care. > :-) -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL - 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/