fast clock wreaks havoc on amd64 dual core - hp1250n
Hello all,
I've spent the last 5 days trying to fix an issue with a brand new
hp a1250n dual core athlon64 machine. ATI motherboard with embedded
radeon xpress 200 graphics. I've installed the pure64 sarge
distribution. This is my first 64 bit debian attempt, although I am
running a 2 cpu opteron workstation with suse at work.
The system in many ways okay, but there is a serious problem with
interrupts and clock speed which wreaks general havoc on the machine.
The clock is running about 2x speed - I think perhaps two clock ticks
(from each core?) are happening for each one that should. X windows
keyboard behavior is quite erratic, I often get 2-4 chars repeated for
each key typed. I believe this is consistent with lots of interrupt
activity?
Summary of my experiments so far:
2.6.13.4 kernel
1. turning off smp in kernel compile configuration does not correct the
problem.
2. no_timer_check and/or notsc does not reliably correct the problem - I
have seen some help for periods of time.
3. moving from athlon64 to generic x86_64 during kernel compile does nothing
4. no_timer_check pci=noacpi pci=routeirq kernel boot option corrects
the 2x clock speed problem, but breaks at lot of other things - I am
running this at the moment so I can use the computer (but my firewire
drive is not recognized, for example).
5. PM_timer kernel compile option does nothing
6. Changing timer frequency does nothing.
I wanted to check with older 2.6 kernels but experience a failed boot on
stock debian 2.6.8 amd64-smp kernel, I don't this is indicative of a
problem other than misconfiguration of grub or devfs subsystems (there
is a pivot_root at boot time that fails)...
some interesting log entries:
kern.log:
Oct 18 14:57:48 localhost kernel: Losing some ticks... checking if CPU
frequency changed.
Oct 18 23:36:50 line kernel: Your time source seems to be instable or
some driver is hogging interupts
Oct 19 05:40:05 line kernel: rtc: lost some interrupts at 2048Hz.
Oct 19 05:49:33 line kernel: rtc: lost some interrupts at 2048Hz.
This seems like it could be related to kernel bug 3927:
http://bugzilla.kernel.org/show_bug.cgi?id=3927
which has been marked as "resolved" but my reading suggest that a
sufficient number of people found workarounds to let the bug subside
rather than fixing it...
In any case, my deep appreciation to anyone who has a solution after
days of kernel recompiles and rebooting with various boot options.
Happy to send more detailed logs and kernel compile options if there is
interest.
Nathan
Reply to: