From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765092AbXGLDf3 (ORCPT ); Wed, 11 Jul 2007 23:35:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757254AbXGLDfU (ORCPT ); Wed, 11 Jul 2007 23:35:20 -0400 Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:48045 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1755422AbXGLDfT (ORCPT ); Wed, 11 Jul 2007 23:35:19 -0400 Date: Wed, 11 Jul 2007 20:35:18 -0700 (PDT) Message-Id: <20070711.203518.59469474.davem@davemloft.net> To: rusty@rustcorp.com.au Cc: hch@lst.de, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: lguest, Re: -mm merge plans for 2.6.23 From: David Miller In-Reply-To: <1184210118.6005.719.camel@localhost.localdomain> References: <1184208521.6005.695.camel@localhost.localdomain> <20070711.195126.02300228.davem@davemloft.net> <1184210118.6005.719.camel@localhost.localdomain> X-Mailer: Mew version 5.1.52 on Emacs 21.4 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Rusty Russell Date: Thu, 12 Jul 2007 13:15:18 +1000 > Sure, the process has /dev/lguest open, so I can do something in the > close routine. Instead of keeping a reference to the tsk, I can keep a > reference to the struct lguest (currently it doesn't have or need a > refcnt). Then I need another lock, to protect lg->tsk. > > This seems like a lot of dancing to avoid one export. If it's that > important I'd far rather drop the code and do a normal wakeup under the > big lguest lock for 2.6.23. I'm not against the export, so use if it really helps. Ref-counting just seems clumsy to me given how the hw assisted virtualization stuff works on platforms I am intimately familiar with :)