[ofa-general] [PATCH] ipoib: refresh path when remote lid changes

[Yossi Etigin]

On 31/07/09 22:40, Jason Gunthorpe wrote:
> On Fri, Jul 31, 2009 at 07:13:12PM +0300, Yossi Etigin wrote:
> 
>> What if we query the remote port LMC once, when the path is
>> resolved, and then use it to mask the LID until the path is
>> refreshed again?
> 
> What are you trying to fix here? Most SMs have a persistent LID
> stability feature, so why would the LID change very often anyhow?
> 
> Jason
>

We have customers with large fabrics and different machines/operation systems, 
where the LID does not always stay the same.They are experiencing loss of
IPoIB connectivity. The patch above solved that. Besides, according to the 
IB spec, LIDs are not persistent and can change (although most SM today do
try to keep them persistent).

Regarding LMC, that is less likely to change, so if we handle constant LMC
correctly and if LMC is changed the behaviour is as it was before the patch,
I think it can be OK.

What do you think?

--Yossi