From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 10 Oct 2003 12:39:04 -0400 From: Bill Fink To: Gabriel Paubert Cc: linuxppc-dev@lists.linuxppc.org, Bill Fink Subject: Re: Time precision, adjtime(x) vs. gettimeofday Message-Id: <20031010123904.24a8c6cd.billfink@mindspring.com> In-Reply-To: <20031010073314.GA14632@iram.es> References: <20031010011254.078c84a8.billfink@mindspring.com> <20031010073314.GA14632@iram.es> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: On Fri, 10 Oct 2003, Gabriel Paubert wrote: > On Fri, Oct 10, 2003 at 01:12:54AM -0400, Bill Fink wrote: > > > > This discussion prompted me to finally ask about another clock related > > problem I see on the 867 MHz G4 systems at work. The clocks on these > > systems continuously run 0.2% slow (about 3 minutes per day). Apparently > > this is more than ntp can adjust for (using scaling), as I get many of > > these error messages in the log: > > Indeed, the limit of NTP is about 500ppm (0.05%) AFAIR. Anything higher > and you go into period time steps like the one you report. > > 2.4.20 is recent enough and should not have this kind of problems. > > What is the initial decrementer frequency from boot messages log? clifford% dmesg | grep -i decr time_init: decrementer frequency = 33.290001 MHz > What is the timebase frequency from OF? > (od -td4 /proc/device-tree/cpus/PowerPC,G4/timebase-frequency) clifford% od -td4 /proc/device-tree/cpus/PowerPC,G4/timebase-frequency 0000000 33290001 0000004 -Bill ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/