NForce2, Ross Dickson's timer patch on 2.6.1
Quoted 8 lines · Jesse Allen
Hi Ross,
I have a version of your timer patch (
io_apic.c) for kernel 2.6.1. It is attached. I have been monitoring a problem with it. It seems that with the patch, I gain 1 seconds time over 10 minutes (roughly). So I gain about 2-3 mintues a day. I haven't taken exact measurements, but I know it ends up about 20 minutes difference after a week. This is not good, which would require resetting the time often.
Not a good thing.
I have not noticed it on my patched 2.4.24 kernel, it seems to keep good time with the clock on the wall. I will have to check further to be certain. I do not run 2.6.x by default as yet.
Quoted 14 lines
I tried the 2.6.1 kernel without the timer patch. The timer is now back in PIC mode, and interrupt 7 has the old noise. Synched the time with my watch. At first, I noticed no gain in time over 10 minutes. However the next day, I found it gained 1-2 seconds. Now it is about 7 seconds ahead a few days later now. This is much better.
So I'm left to thinking, the patch does two things, maybe one thing right, and one possibly very wrong:
1) It does place the timer in APIC mode.
2) But the timer seems to be fed extra interrupts, maybe the same that is found on irq 7 without the patch (is this possible?)
Quoted 8 lines
I remember someone making a comment which might explain the issue:
http://marc.theaimsgroup.com/?l=linux-kernel&m=107098440019588&w=2I don't think the patch was much different now than it was then. So I think there is something wrong with setting up the timer this way. I don't know if you worked something out with Maciej. I don't know much about interrupt controller programming so... if maybe you can explain to me anything I'm missing. For now I've dropped the patch.
We looked into the issue, these emails (was my 2.4.23 kernel) indicate that the 8259 PIC is fully masked off when the check timer looked for interrupts.
http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-12/2288.html
http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-12/2375.html
So if there are additional interrupts getting into irq0 then they are very unexpected and may be from an undocumented source? Or perhaps something is different in counting time in 2.6.x wrt 2.4.xx? Could the same interrupt occasionally be getting counted twice or something?
Quoted 7 lines
Jesse
PS: I have run with disconnect on, and without your ack patch since I got that surpise BIOS update. No lockups have occurred in the past month, since that.
So the disconnect problem is a BIOS bug. (Shuttle has not responded)
Quoted 1 line
I would love a bios update like that for my motherboards!
Given Daniel has had lockups with disconnect off.
http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-12/4769.html
And your machine no longer has them with disconnect on, then I now think the cause is something different to the AMD C1 disconnect issue, but what I do not know? I believe AMD are still looking into it as per my support request.
I would really like to hear from Nvidia on this issue, I have tried emailing them, form mailing them and also posting to their linux forum with no success or response. Given its been over a month since my first posting I am having serious second thoughts about my choice of chipsets and motherboards! I currently do not feel very warm and fuzzy about their linux support!
Quoted 1 line
PSS: CC me, I'm not subscribed right now.
Quoted 5 lines · Ross Dickson
Given Daniel has had lockups with disconnect off.
http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-12/4769.html
And your machine no longer has them with disconnect on, then I now think the cause is something different to the AMD C1 disconnect issue, but what I do not know? I believe AMD are still looking into it as per my support request.
Hi Ross,
I feel that I should clarify your point here as I've got a bit confused myself as to which patch does what, etc!
I compiled 2.6.0-test11-mm1 with IOAPIC and APIC support (never had used these options before). Within minutes I met my first lockup ever on this PC. (This kernel included the other recent nforce2 patches: nforce2-disconnect-quirk.patch and +nforce2-apic.patch)
I then tried your patches with default settings, and I thought that the problem was solved, as you can see in the URL you referenced. That was a false alarm, I did then meet another lockup a few hours later, and another one a few hours after that. I then reverted out the nforce2-disconnect-quirk patch (as per your suggestion), and started booting with the apic_tack=2 argument.
See: http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-12/5259.html
No lockups since then, but I have been experiencing the clock skew.
But, there might be more to it. I had forgotten up until now, but I am using this code in my /etc/conf.d/local.start :
setpci -v -H1 -s 0:0.0 6F=$(printf %x $((0x$(setpci -H1 -s 0:0.0 6F) | 0x10)))
and this one in /etc/conf.d/local.stop :
setpci -v -H1 -s 0:0.0 6F=$(printf %x $((0x$(setpci -H1 -s 0:0.0 6F) & 0xef)))
I got these codes from http://www.tldp.org/HOWTO/Athlon-Powersaving-HOWTO/approaches.html#commandline a while back - they are supposed to enable powersaving and make your CPU run cooler. I ran a test when I originally started using this, and I did find that my CPU ran cooler when idle after I had ran these commands.
I don't know if this would influence my systems behaviour with/without the various patches that have been flying around.. but I hope you can make some sense out of it and continue bugging AMD/nvidia!
Quoted 5 lines
I would really like to hear from Nvidia on this issue, I have tried emailing them, form mailing them and also posting to their linux forum with no success or response. Given its been over a month since my first posting I am having serious second thoughts about my choice of chipsets and motherboards! I currently do not feel very warm and fuzzy about their linux support!
I'd certainly investigate a different type of chipset on my next board, if I knew of a manufacturer that they *would* approach issues like this one out in the open...
Daniel
Quoted 8 lines
But, there might be more to it. I had forgotten up until now, but I am using this code in my
/etc/conf.d/local.start:
setpci -v -H1 -s 0:0.0 6F=$(printf %x $((0x$(setpci -H1 -s 0:0.0 6F) |0x10)))and this one in
/etc/conf.d/local.stop:
setpci -v -H1 -s 0:0.0 6F=$(printf %x $((0x$(setpci -H1 -s 0:0.0 6F) &0xef)))I got these codes from http://www.tldp.org/HOWTO/Athlon-Powersaving-HOWTO/approaches.html#commandline
Well you are putting disconnect to "on" on boot and "off" on shutdown, if I am not mistaken. The quirk wanted to take it turn it off on boot time, so strange it lead to locking to you. I have locking problems intorduced with 2.6.1 mm line. Trying to find out, what is the case...
I haven't tried Ross' patches, btw.
Prakash