PATCH/RFC: [kdump] fix APIC shutdown sequence
martin.wilck at fujitsu-siemens.com
Wed Aug 8 08:04:38 EDT 2007
>>> How bad is it if you just run with irqpoll in the kdump kernel?
>>> If running with irqpoll is usable that is probably preferable
>>> to putting in a hardware work around we can survive without.
>> Yes, I tried that. No effect.
> Martin, at least irpoll should have worked. I am assuming your timer
> interrupts are coming in second kernel. In that case we are not
> dependent at all on actually receiving device interrupt. Polling should
> take care of it.
You are right. I just tested irqpoll again , and it does works even if the error
(detected by the IRR bit set in the IO-APIC) occurs.
I have no idea what went wrong when I tried "irqpoll" last time. But I was
using a different kernel, controller firmware, driver, and HW configuration,
so it can probably be explained somehow. Unfortunately, the unsuccessful early
attempts caused me to conclude prematurely that "irqpoll" didn't help. I admit
I didn't understand "irqpoll" fully until just now.
> What is that device which is not working? What is the success criterion?
It's a LSI megaraid_sas "zero channel RAID" (ZCR) controller. The system has an
on-board LSI 1068 (mptsas). If you put the ZCR in a certain PCI slot, the
1068 is hidden from the system, which sees the megaraid_sas controller
(1000:0413) instead of the 1068. The ZCR internally uses the 1068 as low-level
The success criterion was that the disks on the ZCR were successfully detected
and the dump was written.
PRIMERGY System Software Engineer
FSC IP ESP DE6
Fujitsu Siemens Computers GmbH
Tel: ++49 5251 8 15113
Fax: ++49 5251 8 20409
Email: mailto:martin.wilck at fujitsu-siemens.com
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