From owner-svn-src-head@FreeBSD.ORG  Mon Apr  4 17:00:50 2011
Return-Path: <owner-svn-src-head@FreeBSD.ORG>
Delivered-To: svn-src-head@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 82864106564A;
	Mon,  4 Apr 2011 17:00:50 +0000 (UTC)
	(envelope-from jkim@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c])
	by mx1.freebsd.org (Postfix) with ESMTP id 73A5A8FC14;
	Mon,  4 Apr 2011 17:00:50 +0000 (UTC)
Received: from svn.freebsd.org (localhost [127.0.0.1])
	by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id p34H0oOh089939;
	Mon, 4 Apr 2011 17:00:50 GMT (envelope-from jkim@svn.freebsd.org)
Received: (from jkim@localhost)
	by svn.freebsd.org (8.14.3/8.14.3/Submit) id p34H0oS8089937;
	Mon, 4 Apr 2011 17:00:50 GMT (envelope-from jkim@svn.freebsd.org)
Message-Id: <201104041700.p34H0oS8089937@svn.freebsd.org>
From: Jung-uk Kim <jkim@FreeBSD.org>
Date: Mon, 4 Apr 2011 17:00:50 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
	svn-src-head@freebsd.org
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Cc: 
Subject: svn commit: r220333 - head/sys/dev/acpica
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.5
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/listinfo/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: Mon, 04 Apr 2011 17:00:50 -0000

Author: jkim
Date: Mon Apr  4 17:00:50 2011
New Revision: 220333
URL: http://svn.freebsd.org/changeset/base/220333

Log:
  Lower the bar for ACPI-fast on virtual machines.  The current logic depends
  on the fact that real hardware has almost fixed cost to read the ACPI timer.
  It is virtually always false for hardware emulation and it makes no sense to
  read it multiple times, which is already quite expensive for full emulation.

Modified:
  head/sys/dev/acpica/acpi_timer.c

Modified: head/sys/dev/acpica/acpi_timer.c
==============================================================================
--- head/sys/dev/acpica/acpi_timer.c	Mon Apr  4 16:59:46 2011	(r220332)
+++ head/sys/dev/acpica/acpi_timer.c	Mon Apr  4 17:00:50 2011	(r220333)
@@ -327,14 +327,15 @@ acpi_timer_test()
     }
     intr_restore(s);
 
-    if (max - min > 2)
+    delta = max - min;
+    if (delta > 2 && vm_guest == VM_GUEST_NO)
 	n = 0;
     else if (min < 0 || max == 0)
 	n = 0;
     else
 	n = 1;
     if (bootverbose)
-	printf(" %d/%d", n, max-min);
+	printf(" %d/%d", n, delta);
 
     return (n);
 }