lkml.org 
[lkml]   [2004]   [Jun]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [discuss] x86-64: double timer interrupts in recent 2.4.x
Hi!

I have Suse 9.0 and dual Opteron on MSI K8T Master 2 motherboard.
I also get interrupts only on one cpu and my clock is ticking strange,
so I have to synchronize it with NTP server frequently.

This is from my system:
CPU0 CPU1
0: 30434 16139843 IO-APIC-edge timer
1: 944 0 IO-APIC-edge keyboard
2: 0 0 XT-PIC cascade
14: 30 1 IO-APIC-edge ide0
16: 657371 0 IO-APIC-level eth0
20: 261267 0 IO-APIC-level libata
NMI: 694146 873271
LOC: 16167676 16167576
ERR: 1
MIS: 0

Linux www 2.4.21-226-smp #1 SMP Tue Jun 15 09:14:10 UTC 2004 x86_64
x86_64 x86_64 GNU/Linux


I am also running irq_balance and acpi=off set from grub boot menu.
Without acpi=off system never boots.

Is there any solution, so clock will work OK and interrupts will be on
both CPUs?

MIlan


Peter Cordes wrote:

> Nobody replied to this message on debian-amd64@lists.d.o, or
> discuss@x86-64.org. Hopefully I've found the right places to send this this
> time around. Actually, Roland Fehrenbacher saw my message in a list archive
> and mailed me to confirm that he saw the same double-speed clock problem on
> two different machines, so it's not just Tyan S2880 boards. He suggested I
> mail Andi and lkml, so here goes. (I haven't tested again with anything more
> recent than 2.4.27-pre2, so if this is fixed, sorry.)
>
> -----
>
> I just noticed that on my Opteron cluster, the nodes that are running 64bit
> kernels have their clocks ticking at double speed. This happens with
> Linux 2.4.26, and 2.4.27-pre2, compiled with gcc 3.3.3 (Debian 20040401) in a
> Debian pure64 chroot. Linux 2.4.25, compiled on Debian Woody + bi-arch gcc
> 3.3.2 20030908, does _not_ have the problem. The config options were pretty
> much the same for all kernels, and all the kernels are plain vanilla flavour
> from www.ca.kernel.org.
>
> If I run ntpdate to set the clock, then 10 seconds later it will be 10
> seconds fast. Running date(1), the system time advances 20 seconds in 10
> seconds of real time. (I haven't done anything weird with adjtimex(8).)
> time sleep 10 takes 5 seconds, but bash reports its real time as 10 seconds.
> The timer interrupt counter is increasing at a rate of 200/real second, so
> it seems like the system is getting timer interrupts twice as fast as it
> should. (With 2.4.25, it is 100/sec, same as HZ).
>
> Linux says it is using the PIT and TSC timers. I have HPET enabled in my
> Linux config, but I guess Tyan's S2880 mobo doesn't have one. This is a
> dual-Opteron 240 machine, BTW.
>
> i386 Linux on the same machines has no problems with timekeeping. (But I
> haven't tested versions later than 2.4.25 in legacy mode.)
>
> I spent some time poking around the timer code that increments xtime, but I
> guess the fact that the timer irqs are coming at double speed indicates that
> the problem lies elsewhere. Maybe the code that sets up the timer?
>
> $ uname -a
> Linux node6.cs.dal.ca 2.4.26 #2 SMP Fri May 14 14:46:42 ADT 2004 x86_64 x86_64 x86_64 GNU/Linux
> $ cat /proc/interrupts
> CPU0 CPU1
> 0: 4415908 0 IO-APIC-edge timer
> 1: 2 0 IO-APIC-edge keyboard
> 2: 0 0 XT-PIC cascade
> 9: 0 0 IO-APIC-level acpi
> 14: 17861 1 IO-APIC-edge ide0
> 19: 0 0 IO-APIC-level usb-ohci, usb-ohci
> 24: 563942 0 IO-APIC-level eth0
> 25: 564331 0 IO-APIC-level eth1
> NMI: 19097 19097
> LOC: 2211090 2211095
> ERR: 0
> MIS: 0
>
> Only CPU0 is getting the timer interrupt, but at least we know it's not
> that both CPUs are getting the timer interrupt. (Both CPUs get 100 LOC:
> (local APIC) interrupts/sec, but that happens on the non-buggy 2.4.25, too.)
>
> Thanks for any help,
>
> I'm not subscribed to the lkml, so please CC me on any followups.
>
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:04    [W:0.048 / U:0.732 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site