Re: megasas stops I/O when running kernel as dom0 under xen4.1/4.2

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 22/08/11 10:05, Andrew Cooper wrote:
> On 19/08/11 19:10, Andreas Olsowski wrote:
>> Am 19.08.2011 18:49, schrieb Andrew Cooper:
>>
>>> The only change you need to make is in megasas_probe_one() in
>>> megaraid_sas_base.c
>>>
>>> Add a call to pci_enable_msi(pdev) immediately after the current
>> call to
>>> pci_set_master(pdev);
>>>
>>> ~Andrew
>>>
>> Yep, that works fine. Removed the module option as well.
>>
>> root@tarballerina:~# cat /proc/interrupts  |grep mega
>> 2236:      69010          0          0          0          0         
>> 0          0          0  xen-pirq-msi       megasas
>>
>> The same procedure that would have lead to almost instant errors has
>> not brought them to appear again.
>>
> Good.  This is what we are seeing as well.  I am still awaiting a reply
> from LSI on this topic.
>
> Unfortunately, this does point to a regression in the way Xen deals with
> legacy interrupts.

Out of interest, on all 3 of your boxes with the megaraid_sas cards,
could you gather the io_apic information?

It is the z xen debug key on the serial console (or alternatively put
apic_verbosity=debug on the xen commandline and the information gets
dumped into the dmesg)

-- 
Andrew Cooper - Dom0 Kernel Engineer, Citrix XenServer
T: +44 (0)1223 225 900, http://www.citrix.com