From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764893AbYAaDdd (ORCPT ); Wed, 30 Jan 2008 22:33:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754492AbYAaDdZ (ORCPT ); Wed, 30 Jan 2008 22:33:25 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:50732 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753792AbYAaDdY (ORCPT ); Wed, 30 Jan 2008 22:33:24 -0500 Date: Thu, 31 Jan 2008 03:33:20 +0000 From: Christoph Hellwig To: "Denis V. Lunev" Cc: trond.myklebust@fys.uio.no, hch@infradead.org, linux-kernel@vger.kernel.org, xemul@openvz.org, devel@openvz.org Subject: Re: [PATCH] [NFS]: Lock daemon start/stop rework. Message-ID: <20080131033320.GA15067@infradead.org> References: <1201693294-11460-1-git-send-email-den@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1201693294-11460-1-git-send-email-den@openvz.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 30, 2008 at 02:41:34PM +0300, Denis V. Lunev wrote: > The pid of the locking daemon can be substituted with a task struct > without a problem. Namely, the value if filled in the context of the lockd > thread and used in lockd_up/lockd_down. > > It is possible to save task struct instead and use it to kill the process. > The safety of this operation is guaranteed by the RCU, i.e. task can't > disappear without passing a quiscent state. We have a patch series pending on the nfs list that does this plus a lot more in the area.