From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx123.postini.com [74.125.245.123]) by kanga.kvack.org (Postfix) with SMTP id 38CA46B0044 for ; Sat, 1 Dec 2012 13:56:12 -0500 (EST) Message-ID: <50BA52B6.2010009@redhat.com> Date: Sat, 01 Dec 2012 13:55:50 -0500 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [RFC PATCH] mm/migration: Remove anon vma locking from try_to_unmap() use References: <1354305521-11583-1-git-send-email-mingo@kernel.org> <20121201094927.GA12366@gmail.com> <20121201122649.GA20322@gmail.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Linus Torvalds Cc: Ingo Molnar , Linux Kernel Mailing List , linux-mm , Peter Zijlstra , Paul Turner , Lee Schermerhorn , Christoph Lameter , Mel Gorman , Andrew Morton , Andrea Arcangeli , Thomas Gleixner , Johannes Weiner , Hugh Dickins On 12/01/2012 01:38 PM, Linus Torvalds wrote: > On Sat, Dec 1, 2012 at 4:26 AM, Ingo Molnar wrote: >> >> >> So as a quick concept hack I wrote the patch attached below. >> (It's not signed off, see the patch description text for the >> reason.) > > Well, it confirms that anon_vma locking is a big problem, but as > outlined in my other email it's completely incorrect from an actual > behavior standpoint. > > Btw, I think the anon_vma lock could be made a spinlock The anon_vma lock used to be a spinlock, and was turned into a mutex by Peter, as part of an effort to make more of the VM preemptible. -- All rights reversed -- 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