Advanced Programmable Interrupt Controller (APIC)?
We have a number of DELL boxes in house. The most recent a 6400 (quad p4 box). Also a couple
of dual boxes. They all lock up intermittantly when APIC is enabled. There seems to be no solid way of reproducing the hangs they just hang randomly. With APIC disabled they do not.
The app that we have to run on these boxes requires that APIC is enabled for irq affinity.
It is a soft real-time app that cannot tollerate the jitter. It will run but interrupt latency
is unexceptable without the irq affinity set. I've read on many lists that if you have random lockups that you should disableapic. I've also got a number of NON-DELL boxes that don't exibit this lockup. Now I've also heard that DELL does not properly setup the APIC chip in
the bios because MS os's don't use it. Have no idea if this is true or not. We are using
vanilla kernels (2.4.16) with some process affinity patches applied. I've also noticed that
on the quad boxes (6400) that irqs 0,1,2 cannot be directed to or from a particular processor.
This is also a problem with our app. Mostly it's the lockups that occur with APIC enabled that
is our roadblock for using these nice DELL boxes for our app. Can anyone shed some light on
this.
Thanks in advance
and regards
Signature · 2 lines
Mark Hounschell [email protected]
Mark,
we have a similar problem using PowerEdge 2450s 1550s and 6400s, all our
machines are running with noapic in the lilo config which sounds like it isn't an option for you. I'd be interested where you heard about Dell stuffing up the setup of the APIC chip because we may be able to take this up with them. I've had no reply from the list for the message below (maybe it would be better posted to Kernel Traffic SMP but that's a very quiet list). Anyway maybe the BSD diagnostics will help you investigate this.
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Hello,
just a quickie, our Dell Poweredge boxes - Serverworks motherboard - are continually pumping out IO-APIC errors as I've reported here before, we have three of the same boxes running FreeBSD (limitless file descriptors per process - sorry, we need it!) and I've just noticed that dmesg on these says that:
IO APIC - APIC_IO: Testing 8254 interrupt deliveryAPIC_IO: Broken MP table detected: 8254 is not connected to IOAPIC #0 intpin 2APIC_IO: routing 8254 via 8259 and IOAPIC #0 intpin 0
Does this help anyone diagnose the error??
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Quoted 21 lines · Mark Hounschell
We have a number of DELL boxes in house. The most recent a 6400 (quad p4 box). Also a couple of dual boxes. They all lock up intermittantly when APIC is enabled. There seems to be no solid way of reproducing the hangs they just hang randomly. With APIC disabled they do not.
The app that we have to run on these boxes requires that APIC is enabled for irq affinity. It is a soft real-time app that cannot tollerate the jitter. It will run but interrupt latency is unexceptable without the irq affinity set. I've read on many lists that if you have random lockups that you should disableapic. I've also got a number of NON-DELL boxes that don't exibit this lockup. Now I've also heard that DELL does not properly setup the APIC chip in
the bios because MS os's don't use it. Have no idea if this is true or not. We are using vanilla kernels (2.4.16) with some process affinity patches applied. I've also noticed that on the quad boxes (6400) that irqs 0,1,2 cannot be directed to or from a particular processor. This is also a problem with our app. Mostly it's the lockups that occur with APIC enabled that is our roadblock for using these nice DELL boxes for our app. Can anyone shed some light on this.Thanks in advance
and regards
Signature · 7 lines
---------------- Tim Kay systems administrator Advfn.com Plc - http://www.advfn.com/ [email protected] Tel: 020 7070 0941 Fax: 020 7070 0959
Quoted 7 lines · Tim Kay
Mark,
we have a similar problem using PowerEdge 2450s 1550s and 6400s, all our
machines are running with noapic in the lilo config which sounds like it isn't an option for you. I'd be interested where you heard about Dell stuffing up the setup of the APIC chip because we may be able to take this up with them.
Search the kernel mailing lists at kernel.org for apic and you will find a number of them. Of coarse this is all hear say.
Quoted 3 lines
I've had no reply from the list for the message below (maybe it would be better posted to Kernel Traffic SMP but that's a very quiet list). Anyway maybe the BSD diagnostics will help you investigate this.
I have no experience with BSD.
Quoted 9 lines
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Hello,
just a quickie, our Dell Poweredge boxes - Serverworks motherboard - are continually pumping out IO-APIC errors as I've reported here before, we have three of the same boxes running FreeBSD (limitless file descriptors per process - sorry, we need it!) and I've just noticed that dmesg on these says that:
Quoted 6 lines
IO APIC -
APIC_IO: Testing 8254 interrupt deliveryAPIC_IO: Broken MP table detected: 8254 is not connected to IOAPIC #0 intpin 2APIC_IO: routing 8254 via 8259 and IOAPIC #0 intpin 0Does this help anyone diagnose the error??
I see a message very similar but with the text "Broken_Bios". I don't really know if it is related to the problem or not.
One thing for sure that I can say is that irqs 0,1,2 cannot be directed to or from any processor on these 6400 boxes. They insist on being stuck to all 4 processors. This I do beleive is related to the HANGS that I have.
Signature · 2 lines
Mark Hounschell [email protected]