From owner-freebsd-drivers@FreeBSD.ORG  Mon Sep 26 14:54:11 2011
Return-Path: <owner-freebsd-drivers@FreeBSD.ORG>
Delivered-To: freebsd-drivers@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 39132106564A
	for <freebsd-drivers@freebsd.org>; Mon, 26 Sep 2011 14:54:11 +0000 (UTC)
	(envelope-from nitw.satish@gmail.com)
Received: from sam.nabble.com (sam.nabble.com [216.139.236.26])
	by mx1.freebsd.org (Postfix) with ESMTP id 183508FC13
	for <freebsd-drivers@freebsd.org>; Mon, 26 Sep 2011 14:54:10 +0000 (UTC)
Received: from [192.168.236.26] (helo=sam.nabble.com)
	by sam.nabble.com with esmtp (Exim 4.72)
	(envelope-from <nitw.satish@gmail.com>) id 1R8CJI-0004xK-8N
	for freebsd-drivers@freebsd.org; Mon, 26 Sep 2011 07:37:32 -0700
Date: Mon, 26 Sep 2011 07:37:32 -0700 (PDT)
From: satish kondapalli <nitw.satish@gmail.com>
To: freebsd-drivers@freebsd.org
Message-ID: <1317047852252-4841580.post@n5.nabble.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Subject: one question on mutex.
X-BeenThere: freebsd-drivers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Writing device drivers for FreeBSD <freebsd-drivers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-drivers>, 
	<mailto:freebsd-drivers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-drivers>
List-Post: <mailto:freebsd-drivers@freebsd.org>
List-Help: <mailto:freebsd-drivers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-drivers>,
	<mailto:freebsd-drivers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 26 Sep 2011 14:54:11 -0000

I declared one test mutex  in my char module:
struct mtx test_mutex;

Initialized the above mutex while module loading:
mtx_init(&test_mutex,"cdev_test_mutex",NULL,MTX_DEF);

and in charter device open() function I called mtx_lock() twice. 
mtx_lock(&test_mutex);
mtx_lock(&test_mutex);

Here my question is why the kernel is not blocking on second call of
mtx_lock() ?
Here i initilaized my mutex type as MTX_DEF. All default MTX_DEF are
recursive? (then what is MTX_RECURSE ).


--
View this message in context: http://freebsd.1045724.n5.nabble.com/one-question-on-mutex-tp4841580p4841580.html
Sent from the freebsd-drivers mailing list archive at Nabble.com.