From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758779Ab2ECV1J (ORCPT ); Thu, 3 May 2012 17:27:09 -0400 Received: from corega.com.ru ([195.178.208.66]:41927 "EHLO tservice.net.ru" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1755522Ab2ECV1I (ORCPT ); Thu, 3 May 2012 17:27:08 -0400 Date: Fri, 4 May 2012 01:27:06 +0400 From: Evgeniy Polyakov To: NeilBrown Cc: linux-kernel@vger.kernel.org, Greg Kroah-Hartman Subject: Re: [PATCH] w1: Introduce a slave mutex for serializing IO. Message-ID: <20120503212706.GA26612@ioremap.net> References: <20120425124914.3187a794@notabene.brown> <20120501213958.GA15560@ioremap.net> <20120502162627.50544c8b@notabene.brown> <20120503175857.GA13988@ioremap.net> <20120504070838.5bd23110@notabene.brown> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120504070838.5bd23110@notabene.brown> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 04, 2012 at 07:08:38AM +1000, NeilBrown (neilb@suse.de) wrote: > You can only check the owner on SMP builds, or when debugging is enabled. > So I don't think that approach can work. You can store owner in master device and protect with mutex itself. On non-smp systems it can not be preempted, so can be checked without mutex. -- Evgeniy Polyakov