From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Dan Magenheimer" Subject: RE: [PATCH] clocksource=tsc Date: Wed, 16 Jul 2008 09:42:57 -0600 Message-ID: <20080716094257515.00000080236@djm-pc> References: <20080716074317187.00000080236@djm-pc> Reply-To: "dan.magenheimer@oracle.com" Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20080716074317187.00000080236@djm-pc> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "dan.magenheimer@oracle.com" , Keir Fraser , "Xen-Devel (E-mail)" Cc: Dave Winchell List-Id: xen-devel@lists.xenproject.org Nope, its not ntpd. Everything seemed fine for at least 15-20 minutes, then I went away for awhile and when I checked back an hour later, same weird symptoms as before. I also tried running with nosmp on the xen boot line (and confirmed that only one processor was started). Same results... after about an hour. So it doesn't appear to be a result of cross-CPU time issues. > From: Dan Magenheimer [mailto:dan.magenheimer@oracle.com] > = > I'm thinking the problem may only occur when dom0 is > running ntpd. Maybe "setting" the platform time only > changes one CPU, or sets the platform time differently > than system time? > = > > -----Original Message----- > > From: Keir Fraser [mailto:keir.fraser@eu.citrix.com] > > Sent: Wednesday, July 16, 2008 6:50 AM > > To: dan.magenheimer@oracle.com; Xen-Devel (E-mail) > > Cc: Dave Winchell > > Subject: Re: [PATCH] clocksource=3Dtsc > > = > > = > > That's a weird set of symptoms. Perhaps dom0's sense of = > system time is > > diverging from Xen's? I don't see that CPUs can diverge, if = > > their TSCs are > > in sync, since we shouldn't be dynamically modifying the = > > per-CPU timestamps > > or scale factors. > > = > > -- Keir > > = > > On 16/7/08 13:43, "Dan Magenheimer" = > > wrote: > > = > > > Well now I have to take that back. It DOESN'T work yet. > > > I think I am experiencing "Weirdness can happen..." > > > when booting with clocksource=3Dtsc... I was away from > > > the machine overnight but the symptoms I've seen before > > > are that the system becomes less snappy and eventually > > > grinds to a near-halt. > > > > > > Oddly, I can login most of the way on the console > > > and launch new xterm's in my VNC display, but I never > > > get a prompt, and I can't interrupt a process I left > > > running overnight in another xterm. The time display > > > in gnome seems to have frozen about an hour after > > > I booted. Pinging the machine works but ssh'ing to > > > it doesn't ("Connection closed")