From owner-svn-src-stable@freebsd.org Sat Jan 6 22:56:49 2018 Return-Path: Delivered-To: svn-src-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A54C5DF7F85; Sat, 6 Jan 2018 22:56:49 +0000 (UTC) (envelope-from ian@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 80CB23606; Sat, 6 Jan 2018 22:56:49 +0000 (UTC) (envelope-from ian@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id BA66318BD7; Sat, 6 Jan 2018 22:56:48 +0000 (UTC) (envelope-from ian@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id w06MumWQ001561; Sat, 6 Jan 2018 22:56:48 GMT (envelope-from ian@FreeBSD.org) Received: (from ian@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id w06MumgA001560; Sat, 6 Jan 2018 22:56:48 GMT (envelope-from ian@FreeBSD.org) Message-Id: <201801062256.w06MumgA001560@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: ian set sender to ian@FreeBSD.org using -f From: Ian Lepore Date: Sat, 6 Jan 2018 22:56:48 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r327651 - stable/11/sys/amd64/vmm/io X-SVN-Group: stable-11 X-SVN-Commit-Author: ian X-SVN-Commit-Paths: stable/11/sys/amd64/vmm/io X-SVN-Commit-Revision: 327651 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-stable@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: SVN commit messages for all the -stable branches of the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 06 Jan 2018 22:56:49 -0000 Author: ian Date: Sat Jan 6 22:56:48 2018 New Revision: 327651 URL: https://svnweb.freebsd.org/changeset/base/327651 Log: MFC r325108: Improve the performance of the hpet timer in bhyve guests by making the timer frequency a power of two. This changes the frequency from 10 to 16.7 MHz (2 ^ 24 HZ). Using a power of two avoids roundoff errors when doing arithmetic in sbintime_t units. Testing shows this can fix erratic ntpd behavior in guests using the hpet timer (which is the default for multicore guests). Modified: stable/11/sys/amd64/vmm/io/vhpet.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/amd64/vmm/io/vhpet.c ============================================================================== --- stable/11/sys/amd64/vmm/io/vhpet.c Sat Jan 6 21:37:23 2018 (r327650) +++ stable/11/sys/amd64/vmm/io/vhpet.c Sat Jan 6 22:56:48 2018 (r327651) @@ -51,7 +51,7 @@ __FBSDID("$FreeBSD$"); static MALLOC_DEFINE(M_VHPET, "vhpet", "bhyve virtual hpet"); -#define HPET_FREQ 10000000 /* 10.0 Mhz */ +#define HPET_FREQ 16777216 /* 16.7 (2^24) Mhz */ #define FS_PER_S 1000000000000000ul /* Timer N Configuration and Capabilities Register */