Re: Hard hangs running 6-current.

Frank Mayhar wrote:
> Doug White wrote:
> 
>>Try one of these loader tunables:
>>1. Disabling SMP (kern.smp.disabled=1)
>>2. Disabling mpsafenet (debug.mpsafenet=0)
> 
> 
> I run with debug.mpsafenet=0 (due to a bug I ran into some time ago which I
> haven't looked at recently).
> 
> The current kernel is running with HTT turned off and no SMP builtin.  So
> kern.smp.disabled=1 is kind of redundant.
> 
> So no dice on either one of these.
> 
> 
>>This may be a symptom of a deadlock we're observing on
>>sparc64 in the network stack.  Either one of these should stop the
>>problem, if its the issue we were seeing earlier today.
> 
> 
> Doesn't look like it, I'm afraid.
> 
> 
>>If you especially adventurous, try setting net.inet.tcp.do_tcpdrain=0
>>instead of the options above.  This might cause mbuf exhaustion but is
>>implicated in the deadlock.
>>
>>This is a total hunch and I may be influenced by the time put in on this
>>issue today :)
> 
> 
> If you're interested, you might take a look at
> 	http://www.freebsd.org/cgi/query-pr.cgi?pr=77751
> It has my results for the day.  Warning:  Lots of ath debug output.  I'm
> pretty sure it's the ath driver that's the problem, particularly in light
> of my most recent results.
> 
> Thanks for the ideas, though.

Other than a busted card the only thing I can think of is you're getting 
an interrupt storm from the MIB counters.  If so try disabling 
HAL_INT_MIB in the driver.  The easiest way to do that is probably to 
force sc_needmib to 0 in ath_attach by disabling the following code:

         /*
          * Check if the device has hardware counters for PHY
          * errors.  If so we need to enable the MIB interrupt
          * so we can act on stat triggers.
          */
         if (ath_hal_hwphycounters(ah))
                 sc->sc_needmib = 1;

If your problem does not go away then I can only suggest trying another 
card.  FWIW I haven't seen this.

	Sam