Re: [linux-audio-user] Re: Realtime Kernel Slows My Clock

On Tuesday 07 February 2006 19:12, Chuck Martin wrote:
> On Tue, Feb 07, 2006 at 09:30:15PM +1100, Loki Davison
loki.davison-at-gmail.com |LAU| wrote:
> > On 2/7/06, Chuck Martin <dsdhpnw02@email-addr-hidden> wrote:
> > > I've been trying to get a realtime kernel running, but every kernel
> > > I've tried with a realtime patch slows my clock to a crawl, which
> > > causes my time (as shown with the date command) to be off. It also
> > > causes any program that has a delay to wait far longer than it should.
> > > "sleep 1" can take anywhere from 10 to 30 seconds.
> > >
> > > My most recent try was with patch-2.6.15-rt16, which I've tried
> > > applying to both the 2.6.15 and 2.6.15.2 kernels, with the same result.
> > > Does anyone have any idea what I could be doing wrong, since no one
> > > else on this list seems to be having this problem.
> >
> > Dual core amd 64 or not?
>
> No and no. 600MHz Pentium III.
>
> Chuck

Hi Chuck. My old Gateway 500 P111 Katmai using
kernel-2.6.10-0.4.rdt.rhfc2.ccrma, and realtime modules "rtirq" and "rtload",
is showing similar problems. I had got NTP up and running a while back, and
initially had problems with ntpd dying when the machine had booted up. With
suggestions from Fernando at Planetccrma, I moved the load point of rtload to
before ntpd loaded, which solved that problem. I was then getting time slips,
even with ntpd running, and problems contacting the ntp Internet servers.
This was severly exaggerated during the night when losing the dial-up
connection, resulting in the system clock stopping. Next day, without
re-connecting to the Internet, using the time and date facility, I'd reset
the time as near as possible, leave the time and date window open, and not
move the mouse pointer or do anything on the machine. After a few minutes the
clock would stop again. Move the mouse pointer, and Bingo, the clock starts
again. I havn't solved the problem on this machine, but it's clearly
connected to realtime, and reverting to using the original kernel-2.6.5-1.358
(no realtime), the problem is resolved, and the clock is rock steady, with no
problems with ntp contacting the Internet servers.

Strangely, the other machine on my network. An i-Friend 1.3Ghz celeron, also,
in this example running FC2, with the same planetccrma kernel with the 2
realtime modules, has no clock problems. This machine, again with ntpd
enabled, retrieves it's time from the machine with the problems. Even with
the terrible time slips (clock stopped) on the Gateway, the i-Friend machines
clock stayed on time.

Incidentally. The main reason that I enabled NTP was because I'd been getting
time slips on the Gateway machine, but obviously this is a realtime problem,
specific to this machine. Processor problem? I notice that your P111 is only
a bit faster than mine, and strange that my other machine with the same setup
shows no time slips.

I have posted this problem to questions@email-addr-hidden, but with no replies.

Nigel.
Received on Wed Feb 8 00:15:07 2006