From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: [PATCH 20/25] mm: Simplify anon_vma refcounts Date: Wed, 26 Jan 2011 06:16:08 +1000 Message-ID: References: <20110125173111.720927511@chello.nl> <20110125174908.262260777@chello.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:58261 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752101Ab1AYURB (ORCPT ); Tue, 25 Jan 2011 15:17:01 -0500 In-Reply-To: <20110125174908.262260777@chello.nl> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Peter Zijlstra 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 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?) Linus