Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751668AbZL1Ij6 (ORCPT ); Mon, 28 Dec 2009 03:39:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751330AbZL1Ij5 (ORCPT ); Mon, 28 Dec 2009 03:39:57 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:37946 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751281AbZL1Ij4 (ORCPT ); Mon, 28 Dec 2009 03:39:56 -0500 Subject: Re: [RFC PATCH] asynchronous page fault. From: Peter Zijlstra To: KAMEZAWA Hiroyuki Cc: "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "minchan.kim@gmail.com" , cl@linux-foundation.org In-Reply-To: <20091228093606.9f2e666c.kamezawa.hiroyu@jp.fujitsu.com> References: <20091225105140.263180e8.kamezawa.hiroyu@jp.fujitsu.com> <1261915391.15854.31.camel@laptop> <20091228093606.9f2e666c.kamezawa.hiroyu@jp.fujitsu.com> Content-Type: text/plain; charset="UTF-8" Date: Mon, 28 Dec 2009 09:30:47 +0100 Message-ID: <1261989047.7135.3.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 736 Lines: 19 On Mon, 2009-12-28 at 09:36 +0900, KAMEZAWA Hiroyuki wrote: > > > The idea is to let the RCU lock span whatever length you need the vma > > for, the easy way is to simply use PREEMPT_RCU=y for now, > > I tried to remove his kind of reference count trick but I can't do that > without synchronize_rcu() somewhere in unmap code. I don't like that and > use this refcnt. Why, because otherwise we can access page tables for an already unmapped vma? Yeah that is the interesting bit ;-) -- 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/