From owner-p4-projects@FreeBSD.ORG  Fri Oct 21 19:25:54 2011
Return-Path: <owner-p4-projects@FreeBSD.ORG>
Delivered-To: p4-projects@freebsd.org
Received: by hub.freebsd.org (Postfix, from userid 32767)
	id 9D8F51065674; Fri, 21 Oct 2011 19:25:54 +0000 (UTC)
Delivered-To: perforce@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 60283106566C
	for <perforce@freebsd.org>; Fri, 21 Oct 2011 19:25:54 +0000 (UTC)
	(envelope-from jhb@freebsd.org)
Received: from skunkworks.freebsd.org (skunkworks.freebsd.org
	[IPv6:2001:4f8:fff6::2d])
	by mx1.freebsd.org (Postfix) with ESMTP id 4D7D48FC0C
	for <perforce@freebsd.org>; Fri, 21 Oct 2011 19:25:54 +0000 (UTC)
Received: from skunkworks.freebsd.org (localhost [127.0.0.1])
	by skunkworks.freebsd.org (8.14.4/8.14.4) with ESMTP id p9LJPslF062052
	for <perforce@freebsd.org>; Fri, 21 Oct 2011 19:25:54 GMT
	(envelope-from jhb@freebsd.org)
Received: (from perforce@localhost)
	by skunkworks.freebsd.org (8.14.4/8.14.4/Submit) id p9LJPsvZ062049
	for perforce@freebsd.org; Fri, 21 Oct 2011 19:25:54 GMT
	(envelope-from jhb@freebsd.org)
Date: Fri, 21 Oct 2011 19:25:54 GMT
Message-Id: <201110211925.p9LJPsvZ062049@skunkworks.freebsd.org>
X-Authentication-Warning: skunkworks.freebsd.org: perforce set sender to
	jhb@freebsd.org using -f
From: John Baldwin <jhb@FreeBSD.org>
To: Perforce Change Reviews <perforce@freebsd.org>
Precedence: bulk
Cc: 
Subject: PERFORCE change 200538 for review
X-BeenThere: p4-projects@freebsd.org
X-Mailman-Version: 2.1.5
List-Id: p4 projects tree changes <p4-projects.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/p4-projects>,
	<mailto:p4-projects-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/p4-projects>
List-Post: <mailto:p4-projects@freebsd.org>
List-Help: <mailto:p4-projects-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/p4-projects>,
	<mailto:p4-projects-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 21 Oct 2011 19:25:54 -0000

http://p4web.freebsd.org/@@200538?ac=10

Change 200538 by jhb@jhb_jhbbsd on 2011/10/21 19:25:05

	Drop the default FADV_WILLNEED implementation as it doesn't
	really work and marking any pages that happen to be in RAM as
	active isn't really the right approach either.  Instead, punt
	and require each FS to implement this.

Affected files ...

.. //depot/projects/fadvise/sys/kern/vfs_default.c#3 edit

Differences ...

==== //depot/projects/fadvise/sys/kern/vfs_default.c#3 (text+ko) ====

@@ -46,7 +46,6 @@
 #include <sys/lock.h>
 #include <sys/lockf.h>
 #include <sys/malloc.h>
-#include <sys/mman.h>
 #include <sys/mount.h>
 #include <sys/mutex.h>
 #include <sys/namei.h>
@@ -997,20 +996,10 @@
 	switch (ap->a_advice) {
 	case FADV_WILLNEED:
 		/*
-		 * Apply the request to the backing VM object.
-		 *
-		 * XXX: madvise(MADV_WILLNEED) will not do readahead on
-		 * a file, perhaps FADV_WILLNEED should.
+		 * Do nothing for now.  Filesystems should provide a
+		 * custom method which starts an asynchronous read of
+		 * the requested region.
 		 */
-		start = trunc_page(ap->a_start);
-		end = round_page(ap->a_end);
-		vfslocked = VFS_LOCK_GIANT(vp->v_mount);
-		vn_lock(vp, LK_SHARED | LK_RETRY);
-		if (vp->v_object != NULL)
-			vm_object_madvise(vp->v_object, OFF_TO_IDX(start),
-			    atop(end - start), MADV_WILLNEED);
-		VOP_UNLOCK(vp, 0);
-		VFS_UNLOCK_GIANT(vfslocked);
 		error = 0;
 		break;
 	case FADV_DONTNEED: