[openib-general] Re: uCM kernel oops

[Arlin Davis]

Libor Michalek wrote:

>On Tue, Jul 19, 2005 at 11:10:56AM -0700, Arlin Davis wrote:
>  
>
>>Hi Libor,
>>
>>I am running uCM and uAT with uDAPL and occasionally hit the following. 
>>Can you take a look?
>>
>>Jul 19 11:10:18 iclust-19 kernel: UCM: Write. cmd <1> in <4> out <0> len 
>><12>
>>Jul 19 11:10:18 iclust-19 kernel: UCM: Event. CM ID <2> event <7>
>>Jul 19 11:10:18 iclust-19 kernel: UCM: Destroyed CM ID <2>
>>Jul 19 11:10:18 iclust-19 kernel: Unable to handle kernel paging request 
>><ffffffff880a10c8>{:ib_ucm:ib_ucm_ctx_put+120}
>>Trace:<ffffffff880a183f>{:ib_ucm:ib_ucm_event_handler+1199}
>>    
>>
>
>  Looks like a race between the destroy command and a DREQ received
>event. From looking at the code, it looks like it's possible for
>two threads (cm event and userspace) to call ctx_put at the same
>time and both try to perform the final zero referece object destroy.
>Is this easily reproducible? Can you try the following patch?
>
>  
>
I am having difficulty reproducing.

>-Libor
>
>  
>