Please help me diagnose this crazy VMWare/FreeBSD 8.x crash

[Andrew Boyer]

On May 21, 2012, at 12:41 PM, Mark Felder wrote:

> OK guys I've been talking with another user who can recreate this crash and the last bit of information we've learned seems to be leaning towards interrupts/IRQ issues like someone (bz@ perhaps?) suggested.
> 
> I'm still trying to test this myself, but the other user was able to recreate my crash pretty much on demand. The fix was to not use the first NIC in the VM because it will always share an IRQ with mpt0. Once mpt0 is on its own the crash does not seem to be reproducible anymore.
> 
> Before:
> 
> $ vmstat -i
> interrupt                          total       rate
> irq1: atkbd0                         378          0
> irq6: fdc0                             9          0
> irq15: ata1                           34          0
> irq16: em1                        687237          1
> irq18: em0 mpt0                319094024        539
> cpu0: timer                    236770821        400
> Total                          556552503        940
> 
> After:
> 
> $ vmstat -i
> interrupt                          total       rate
> irq1: atkbd0                          38          0
> irq6: fdc0                             9          0
> irq15: ata1                           34          0
> irq16: em1                          2811         15
> irq17: em2                             5          0
> cpu0: timer                        71013        398
> irq256: mpt0                       12163         68
> Total                              86073        483
> 
> 
> Is there any other way we can make mpt0 get its own dedicated IRQ without having to do this? The problem is that it causes us to have to make rc.conf changes, pf.conf changes, and who knows what other software could be on these machines that is trying to bind to a specific NIC...
> 
> 
> Thanks!
> 

You could try switching mpt to MSI.  MSI interrupts are never shared.  Add this to /boot/device.hints:

> hint.mpt.0.msi_enable="1"


-Andrew

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Andrew Boyer	aboyer at averesystems.com