From mboxrd@z Thu Jan 1 00:00:00 1970 From: Antoine Martin Subject: Re: recommended clock source Date: Mon, 03 Aug 2009 15:11:44 +0700 Message-ID: <4A769BC0.8010909@nagafix.co.uk> References: <4A768B3B.6050402@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Kent Tong , kvm@vger.kernel.org To: dlaor@redhat.com Return-path: Received: from mamba.nagafix.co.uk ([194.145.196.68]:35100 "EHLO mail.nagafix.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752729AbZHCIME (ORCPT ); Mon, 3 Aug 2009 04:12:04 -0400 In-Reply-To: <4A768B3B.6050402@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hi, Dor Laor wrote: > On 08/03/2009 04:52 AM, Kent Tong wrote: >> Hi, >> >> It seems to be an unsettled issue, but, would any kind soul suggest >> the current >> best practice for setting the clock in Ubuntu Linux and Windows guests? > > For Linux the best source clock is the kvm pv clock (exist from 2.6.27 > and above). # qemu-system-x86_64 -clock ? Available alarm timers, in order of precedence: dynticks hpet rtc unix I see no "pv clock"... Which one should I use then? Did I miss a ./configure or .config option? Cheers Antoine > > For windows, standard acpi HAL uses the rtc clock by default. As long as > you use the -rtc-td-hack it won't drift. > > When the tsc is not stable on the host or the host cpu might get into > deep sleep state (c2), you better use another source clock in the guest > - for windows it should be the pmtimer (using the boot.ini). > >> >> Thanks! >> >> -- >> To unsubscribe from this list: send the line "unsubscribe kvm" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEAREKAAYFAkp2m8AACgkQGK2zHPGK1rtQmACeM7UQJZS8TqVjqixZANKBm2gJ kzMAnAxNjQj73tgRyxhP99dpQ0CpWXLW =HWG8 -----END PGP SIGNATURE-----