From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753435Ab1AYUau (ORCPT ); Tue, 25 Jan 2011 15:30:50 -0500 Received: from casper.infradead.org ([85.118.1.10]:42949 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752101Ab1AYUat convert rfc822-to-8bit (ORCPT ); Tue, 25 Jan 2011 15:30:49 -0500 Subject: Re: [PATCH 20/25] mm: Simplify anon_vma refcounts From: Peter Zijlstra To: Linus Torvalds Cc: Andrea Arcangeli , Avi Kivity , Thomas Gleixner , Rik van Riel , Ingo Molnar , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, Benjamin Herrenschmidt , David Miller , Hugh Dickins , Mel Gorman , Nick Piggin , Paul McKenney , Yanmin Zhang , Hugh Dickins In-Reply-To: References: <20110125173111.720927511@chello.nl> <20110125174908.262260777@chello.nl> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Tue, 25 Jan 2011 21:31:01 +0100 Message-ID: <1295987461.28776.1110.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2011-01-26 at 06:16 +1000, Linus Torvalds wrote: > On Wed, Jan 26, 2011 at 3:31 AM, Peter Zijlstra wrote: > > > > This patch changes the anon_vma refcount to be 0 when the object is > > free. It does this by adding 1 ref to being in use in the anon_vma > > structure (iow. the anon_vma->head list is not empty). > > Why is this patch part of this series, rather than being an > independent patch before the whole series? > > I think this part of the series is the only total no-brainer, ie we > should have done this from the beginning. The preemptability stuff I'm > more nervous about (performance issues? semantic differences?) It relies on patch 19, which moves the anon_vma refcount out from under CONFIG_goo. If however you like it, I can move 19 and this patch up to the start and have that go your way soon. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [PATCH 20/25] mm: Simplify anon_vma refcounts Date: Tue, 25 Jan 2011 21:31:01 +0100 Message-ID: <1295987461.28776.1110.camel@laptop> References: <20110125173111.720927511@chello.nl> <20110125174908.262260777@chello.nl> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: Sender: owner-linux-mm@kvack.org To: Linus Torvalds Cc: Andrea Arcangeli , Avi Kivity , Thomas Gleixner , Rik van Riel , Ingo Molnar , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, Benjamin Herrenschmidt , David Miller , Hugh Dickins , Mel Gorman , Nick Piggin , Paul McKenney , Yanmin Zhang , Hugh Dickins List-Id: linux-arch.vger.kernel.org On Wed, 2011-01-26 at 06:16 +1000, Linus Torvalds wrote: > On Wed, Jan 26, 2011 at 3:31 AM, Peter Zijlstra = wrote: > > > > This patch changes the anon_vma refcount to be 0 when the object is > > free. It does this by adding 1 ref to being in use in the anon_vma > > structure (iow. the anon_vma->head list is not empty). >=20 > Why is this patch part of this series, rather than being an > independent patch before the whole series? >=20 > I think this part of the series is the only total no-brainer, ie we > should have done this from the beginning. The preemptability stuff I'm > more nervous about (performance issues? semantic differences?) It relies on patch 19, which moves the anon_vma refcount out from under CONFIG_goo. If however you like it, I can move 19 and this patch up to the start and have that go your way soon. -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org