From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 29 Apr 2008 15:32:35 +0200 From: Andrea Arcangeli Subject: Re: [PATCH 01 of 12] Core of mmu notifiers Message-ID: <20080429133235.GC8315@duo.random> References: <20080423221928.GV24536@duo.random> <20080424064753.GH24536@duo.random> <20080424095112.GC30298@sgi.com> <20080424153943.GJ24536@duo.random> <20080424174145.GM24536@duo.random> <20080426131734.GB19717@sgi.com> <20080427122727.GO9514@duo.random> <20080429001052.GA8315@duo.random> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org Return-Path: To: Hugh Dickins Cc: Christoph Lameter , Robin Holt , Jack Steiner , Nick Piggin , Peter Zijlstra , kvm-devel@lists.sourceforge.net, Kanoj Sarcar , Roland Dreier , Steve Wise , linux-kernel@vger.kernel.org, Avi Kivity , linux-mm@kvack.org, general@lists.openfabrics.org, akpm@linux-foundation.org, Rusty Russell List-ID: Hi Hugh!! On Tue, Apr 29, 2008 at 11:49:11AM +0100, Hugh Dickins wrote: > [I'm scarcely following the mmu notifiers to-and-fro, which seems > to be in good hands, amongst faster thinkers than me: who actually > need and can test this stuff. Don't let me slow you down; but I > can quickly clarify on this history.] Still I think it'd be great if you could review mmu-notifier-core v14. You and Nick are the core VM maintainers so it'd be great to hear any feedback about it. I think it's fairly easy to classify the patch as obviously safe as long as mmu notifiers are disarmed. Here a link for your convenience. http://www.kernel.org/pub/linux/kernel/people/andrea/patches/v2.6/2.6.25/mmu-notifier-v14/mmu-notifier-core > No, the locking was different as you had it, Andrea: there was an extra > bitspin lock, carried over from the pte_chains days (maybe we changed > the name, maybe we disagreed over the name, I forget), which mainly > guarded the page->mapcount. I thought that was one lock more than we > needed, and eliminated it in favour of atomic page->mapcount in 2.6.9. Thanks a lot for the explanation! -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org