From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joanna Rutkowska Subject: Re: A clocksource question Date: Thu, 11 Mar 2010 02:19:47 +0100 Message-ID: <4B984533.9030402@invisiblethingslab.com> References: <4B962748.90609@invisiblethingslab.com> <4B96DB69.10101@goop.org 4B981997.4030605@invisiblethingslab.com> <56cc3abf-21f6-4178-b00e-0331538080d9@default> <4FA716B1526C7C4DB0375C6DADBC4EA3554D53F1B0@LONPMAILBOX01.citrite.net> <4B983EC9.2030105@invisiblethingslab.com> <4B98421F.7040102@goop.org> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0198160043==" Return-path: In-Reply-To: <4B98421F.7040102@goop.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Jeremy Fitzhardinge Cc: Ian Pratt , "xen-devel@lists.xensource.com" , Dan Magenheimer List-Id: xen-devel@lists.xenproject.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --===============0198160043== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigCF1CC99959221D706ED333FA" This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigCF1CC99959221D706ED333FA Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 11/03/2010 02:06, Jeremy Fitzhardinge wrote: > On 03/10/2010 04:52 PM, Joanna Rutkowska wrote: >> BTW, how does the clocksource=3Djiffies work on a pvops kernel in Dom0= ? >> =20 >=20 > Not very well. clocksource=3Djiffies just sets up timer interrupts at > approx 100ms intervals and assumes that's 100ms. You get very low res > timers and timekeeping. >=20 So, how to explain that there is no wallclock drift *at all*, even in a long run -- uptime of a few days, in Dom0, when it uses the jiffies sourc= e? Anyway, I assume that the "xen" clock source is much more fine grained (1ms?) and so, maybe my kbd hiccups are caused by some code executed by the timer interrupt too frequently (maybe too much code executes per each timer interrupt, because of some other bug)? Just a though... j. --------------enigCF1CC99959221D706ED333FA Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iEYEARECAAYFAkuYRTgACgkQORdkotfEW86aFQCgiZdzbr7PkTVR4SYdLVGmskgT 6lcAoOAsR9CAd+ZZNzQ5hsa8h0cRDGsX =ndlq -----END PGP SIGNATURE----- --------------enigCF1CC99959221D706ED333FA-- --===============0198160043== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel --===============0198160043==--