From owner-freebsd-alpha Mon Mar 17 23:13:27 2003 Delivered-To: freebsd-alpha@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1C49A37B408 for ; Mon, 17 Mar 2003 23:13:26 -0800 (PST) Received: from 12-254-143-62.client.attbi.com (12-254-143-62.client.attbi.com [12.254.143.62]) by mx1.FreeBSD.org (Postfix) with SMTP id E97AE43F85 for ; Mon, 17 Mar 2003 23:13:23 -0800 (PST) (envelope-from soren@byu.edu) Received: (qmail 997 invoked by uid 1001); 18 Mar 2003 07:13:20 -0000 Date: Tue, 18 Mar 2003 00:13:20 -0700 From: Soren Harward To: Andrew Gallatin Cc: freebsd-alpha@FreeBSD.ORG Subject: Re: AS2100 SMP clock skew -- fixed or not? Message-ID: <20030318071319.GA592@gandalf.tmmc.dyndns.org> References: <20030317191924.GA84539@gandalf.tmmc.dyndns.org> <20030317202115.A35066@freebie.xs4all.nl> <15990.8815.810592.704436@grasshopper.cs.duke.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <15990.8815.810592.704436@grasshopper.cs.duke.edu> User-Agent: Mutt/1.4i X-URL: http://home.byu.net/~sth22/ Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Mon 17 Mar 2003 at 14:30:55, Andrew Gallatin said: > Search the arhives. I think there may be a hack you can use in there > somewhere. This is what I ended up doing: In alpha_clock_interrupt() in /usr/src/sys/alpha/alpha/interrupt.c I changed the "#ifdef SMP" lines to "#ifdef SMP_BROKEN_AS2100" (which of course isn't #define'd). I re-compiled and now "sleep 5" actually sleeps for 5 seconds instead of 10. I haven't put this through really rigorous testing yet (the machine's been up for all of a half hour now -- I'm going to let it run overnight without ntpd to see if I still get some minor clock skew). Ideally, we could look to see if DEC_2100_A500 (this particular machine type) is defined in the config to see if we need to tweak this setting, however, GENERIC comes with DEC_2100_A500 #define'd by default, along with #define's for every other machine, so we'd probably need some other flag. Of course, if there's still some clock skew, we'd just need to fix the bug instead :) -- Soren Harward soren@byu.edu To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message