Re: BNX driver problem when mbuf clusters run out

[Matt Thomas <matt%3am-software.com@localhost>]

On Apr 19, 2012, at 6:48 PM, Beverly Schwartz wrote:

> 
> On Apr 19, 2012, at 8:27 PM, Matt Thomas wrote:
> 
>> 
>> On Apr 19, 2012, at 5:08 PM, Beverly Schwartz wrote:
>> 
>>> 
>>> On Apr 19, 2012, at 8:02 PM, Matt Thomas wrote:
>>>> 
>>>> Unfortunately, that can lead to receiver livelock (spend all the time 
>>>> servicing interrupts without making progress).  The best thing to do is 
>>>> pass the packet up the stack and just another packet to the hardware.  
>>>> Instead use bnx_tick to add mbufs if needed.  This gives the stack a 
>>>> chance to run and hopefully free some mbufs.
>>> 
>>> I tried that.  And at first, things move along.  But eventually, 
>>> bnx_rx_intr never gets called, because 
>>> if (sblk->status_rx_quick_consumer_index0 != sc->nw_rx_cons)
>>> in bnx_intr always fails.
>> 
>> For now, can you try the patch at
>> 
>> http://www.netbsd.org/~matt/if_bnx-diff.txt
>> 
>> It's kind of ugly but it is a minimal change.
> 
> Doesn't quite do it.  With this change, the sw_cons index doesn't get 
> incremented.  Next time bnx_rx_intr is called, we'll have the same overwrite 
> problem.  I'm now trying incremeing sw_cons before calling break.  When I 
> left work, it was still running.  Tomorrow morning, I'll see if everything is 
> still intact.

It should get incremented since 

        sw_cons = NEXT_RX_BD(sw_cons);

is after the loop.