From owner-svn-src-head@FreeBSD.ORG  Tue Jun  4 17:23:09 2013
Return-Path: <owner-svn-src-head@FreeBSD.ORG>
Delivered-To: svn-src-head@freebsd.org
Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115])
 by hub.freebsd.org (Postfix) with ESMTP id 858215F7;
 Tue,  4 Jun 2013 17:23:09 +0000 (UTC) (envelope-from alc@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org
 [IPv6:2001:1900:2254:2068::e6a:0])
 by mx1.freebsd.org (Postfix) with ESMTP id 776971037;
 Tue,  4 Jun 2013 17:23:09 +0000 (UTC)
Received: from svn.freebsd.org ([127.0.1.70])
 by svn.freebsd.org (8.14.7/8.14.7) with ESMTP id r54HN9Vl086179;
 Tue, 4 Jun 2013 17:23:09 GMT (envelope-from alc@svn.freebsd.org)
Received: (from alc@localhost)
 by svn.freebsd.org (8.14.7/8.14.5/Submit) id r54HN9lg086178;
 Tue, 4 Jun 2013 17:23:09 GMT (envelope-from alc@svn.freebsd.org)
Message-Id: <201306041723.r54HN9lg086178@svn.freebsd.org>
From: Alan Cox <alc@FreeBSD.org>
Date: Tue, 4 Jun 2013 17:23:09 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
 svn-src-head@freebsd.org
Subject: svn commit: r251391 - head/sys/security/mac
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
 <svn-src-head.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
 <mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 04 Jun 2013 17:23:09 -0000

Author: alc
Date: Tue Jun  4 17:23:09 2013
New Revision: 251391
URL: http://svnweb.freebsd.org/changeset/base/251391

Log:
  Relax the vm object locking in mac_proc_vm_revoke_recurse().  A read lock
  suffices in one place.
  
  Sponsored by:	EMC / Isilon Storage Division

Modified:
  head/sys/security/mac/mac_process.c

Modified: head/sys/security/mac/mac_process.c
==============================================================================
--- head/sys/security/mac/mac_process.c	Tue Jun  4 17:08:26 2013	(r251390)
+++ head/sys/security/mac/mac_process.c	Tue Jun  4 17:23:09 2013	(r251391)
@@ -284,14 +284,14 @@ mac_proc_vm_revoke_recurse(struct thread
 		object = vme->object.vm_object;
 		if (object == NULL)
 			continue;
-		VM_OBJECT_WLOCK(object);
+		VM_OBJECT_RLOCK(object);
 		while ((backing_object = object->backing_object) != NULL) {
-			VM_OBJECT_WLOCK(backing_object);
+			VM_OBJECT_RLOCK(backing_object);
 			offset += object->backing_object_offset;
-			VM_OBJECT_WUNLOCK(object);
+			VM_OBJECT_RUNLOCK(object);
 			object = backing_object;
 		}
-		VM_OBJECT_WUNLOCK(object);
+		VM_OBJECT_RUNLOCK(object);
 		/*
 		 * At the moment, vm_maps and objects aren't considered by
 		 * the MAC system, so only things with backing by a normal