From owner-svn-src-all@FreeBSD.ORG Sun May 11 16:48:37 2014 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 57116C5; Sun, 11 May 2014 16:48:37 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4371A21B0; Sun, 11 May 2014 16:48:37 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.8/8.14.8) with ESMTP id s4BGmbUG071014; Sun, 11 May 2014 16:48:37 GMT (envelope-from markj@svn.freebsd.org) Received: (from markj@localhost) by svn.freebsd.org (8.14.8/8.14.8/Submit) id s4BGmaPx071012; Sun, 11 May 2014 16:48:36 GMT (envelope-from markj@svn.freebsd.org) Message-Id: <201405111648.s4BGmaPx071012@svn.freebsd.org> From: Mark Johnston Date: Sun, 11 May 2014 16:48:36 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-9@freebsd.org Subject: svn commit: r265882 - in stable/9/sys/cddl/dev/dtrace: amd64 i386 X-SVN-Group: stable-9 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 11 May 2014 16:48:37 -0000 Author: markj Date: Sun May 11 16:48:36 2014 New Revision: 265882 URL: http://svnweb.freebsd.org/changeset/base/265882 Log: MFC r236566 (by zml): Fix DTrace TSC skew calculation: The skew calculation here is exactly backwards. We were able to repro it on a multi-package ESX server running a FreeBSD VM, where the TSCs can be pretty evil. Modified: stable/9/sys/cddl/dev/dtrace/amd64/dtrace_subr.c stable/9/sys/cddl/dev/dtrace/i386/dtrace_subr.c Directory Properties: stable/9/sys/ (props changed) Modified: stable/9/sys/cddl/dev/dtrace/amd64/dtrace_subr.c ============================================================================== --- stable/9/sys/cddl/dev/dtrace/amd64/dtrace_subr.c Sun May 11 16:34:17 2014 (r265881) +++ stable/9/sys/cddl/dev/dtrace/amd64/dtrace_subr.c Sun May 11 16:48:36 2014 (r265882) @@ -445,7 +445,7 @@ dtrace_gethrtime() * (see nsec_scale calculations) taking into account 32-bit shift of * the higher half and finally add. */ - tsc = rdtsc() + tsc_skew[curcpu]; + tsc = rdtsc() - tsc_skew[curcpu]; lo = tsc; hi = tsc >> 32; return (((lo * nsec_scale) >> SCALE_SHIFT) + Modified: stable/9/sys/cddl/dev/dtrace/i386/dtrace_subr.c ============================================================================== --- stable/9/sys/cddl/dev/dtrace/i386/dtrace_subr.c Sun May 11 16:34:17 2014 (r265881) +++ stable/9/sys/cddl/dev/dtrace/i386/dtrace_subr.c Sun May 11 16:48:36 2014 (r265882) @@ -454,7 +454,7 @@ dtrace_gethrtime() * (see nsec_scale calculations) taking into account 32-bit shift of * the higher half and finally add. */ - tsc = rdtsc() + tsc_skew[curcpu]; + tsc = rdtsc() - tsc_skew[curcpu]; lo = tsc; hi = tsc >> 32; return (((lo * nsec_scale) >> SCALE_SHIFT) +