SMP support for XLR processors.

[Rui Paulo]

On 20 Apr 2010, at 11:05, Rui Paulo wrote:

> On 20 Apr 2010, at 10:52, C. Jayachandran wrote:
> 
>> On Mon, Apr 19, 2010 at 7:27 PM, C. Jayachandran
>> <c.jayachandran at gmail.com> wrote:
>>> I have a possible cause for the panic with invariants - we should not
>>> schedule the msgring threads unless the smp is completely up. I guess
>>> we start getting message ring interrupts on before the message ring
>>> threads can be scheduled.  I am trying out some changes for this -
>>> will send you a patch if this fixes it.
>> 
>> I've attached a patch that should fix the issue. The cause was the way
>> message ring threads are started on individual cores and the way
>> interrupts are enabled in the core.  I've moved starting message ring
>> threads on other cpus to be a SYSINIT after SMP is started.  I'd
>> thought originally that it was due to some clash with the changes in
>> HEAD - but looks like I was completely off-track there.
>> 
>> Please let me know if you don't get multi-user with 32 cpus with this
>> patch. There is still the original hang in buildworld, but that should
>> be a bug elsewhere
>> 
>> I have a copy at http://sites.google.com/site/cjayachandran/files too
> 
> This works perfectly, thanks!

On further inspection, I noticed that the load avg is now 7.

last pid:  1613;  load averages:  6.99,  6.97,  6.08    up 0+00:30:11  10:32:48
108 processes: 40 running, 24 sleeping, 44 waiting
CPU:  0.0% user,  0.0% nice, 21.9% system,  0.0% interrupt, 78.1% idle
Mem: 8444K Active, 6028K Inact, 37M Wired, 308K Cache, 6800K Buf, 3190M Free
Swap: 

  PID USERNAME  THR PRI NICE   SIZE    RES STATE   C   TIME   WCPU COMMAND
   10 root       32 171 ki31     0G     0G CPU0    0 263:26 2500.00% idle
   17 root        1 -16    -     0K     0G CPU12   2   0:00 100.00% msg_intr12
   15 root        1 -16    -     0K     0G CPU4    2   0:00 100.00% msg_intr4
   16 root        1 -16    -     0K     0G CPU8    2   0:00 100.00% msg_intr8
   20 root        1 -16    -     0K     0G CPU24   1   0:00 100.00% msg_intr24
   19 root        1 -16    -     0K     0G CPU20   1   0:00 100.00% msg_intr20
   21 root        1 -16    -     0K     0G CPU28   1   0:00 100.00% msg_intr28
   18 root        1 -16    -     0K     0G CPU16   1   0:00 100.00% msg_intr16

What are these msg_intrXX kprocs doing?

Regards,
--
Rui Paulo