Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751423Ab0HUPtk (ORCPT ); Sat, 21 Aug 2010 11:49:40 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:48224 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750926Ab0HUPtj (ORCPT ); Sat, 21 Aug 2010 11:49:39 -0400 MIME-Version: 1.0 In-Reply-To: <1282391770.29609.1223.camel@localhost.localdomain> References: <1282391770.29609.1223.camel@localhost.localdomain> From: Linus Torvalds Date: Sat, 21 Aug 2010 08:48:29 -0700 Message-ID: Subject: Re: [RFC] mlock/stack guard interaction fixup To: Ian Campbell Cc: linux-kernel@vger.kernel.org, stable@kernel.org, stable-review@kernel.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Greg KH , Peter Zijlstra , Jeremy Fitzhardinge Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1511 Lines: 32 On Sat, Aug 21, 2010 at 4:56 AM, Ian Campbell wrote: > > I don't know that they are particularly good tests for this change but I > also ran allmodconfig kernel build and ltp on 2.6.35.3+fixes without > issue. Are there any good mlock heavy workloads? mlock itself isn't very interesting, I think more interesting is testing that the doubly linked list handles all the cases correctly. Something that splits mappings, unmaps partial ones etc etc. Running something like Electric Fence is probably a good idea. The happy news is that we really didn't have lots of assignments to vma->vm_next - they were all pretty cleanly separated into just a couple of cases. So I'm pretty confident in the patches. But... > Out of interest, why is there no guard page for the VM_GROWSUP stack > case? Is it just that the memory layout on PA-RISC makes the stack grows > into the heap scenario impossible? No, it's just that I can't find it in myself to care about PA-RISC, so I never wrote the code. I don't think anything else has a grows-up stack. And even if I were to write the code, I couldn't even test it. It should be reasonably easy to do the VM_GROWSUP case too, but somebody with a PA-RISC would need to do it. Linus -- 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/