Proposed 6.2 em RELEASE patch

[Mike Tancsa]

At 08:47 PM 11/12/2006, Scott Long wrote:
>>>2. Try compiling in WITNESS and running the test as before, then break
>>>into the debugger as before.  Run 'show locks'.  I'm not sure how
>>>fruitful this will be, WITNESS might make it unbearably slow.
>>It was in that kernel already
>
>So you're seeing the livelock under load while also having WITNESS 
>enabled?  Have you tried your test without WITNESS?  What about INVARIANTS?

Sorry, by it was in the kernel already, it was from last nights tests 
where you asked me to break into the debugger to see what was going 
on. I figured you would want it in there.  My original tests were all 
without WITNESS and INVARIANTS and they were showing the same 
behaviour (locking up on the management interface) with and without 
WITNESS and INVARIANTS


Removing ADAPTIVE_GIANT seems to be very key in this!  If I remove 
it, the box no longer locks up under a high packet rate! Its still a 
little sluggish on the bge OOB interface, but its not totally locking 
up like before

Running ifstat -b from the management interface, here is the traffic 
pattern first with one blast running and then the second kicks 
in.  The Kbps/s out on em1 drops in half, but the box is still 
responsive and bge1... Certainly responsive enough to see the output of ifstat.



218028.4      0.00      0.00  216389.9      0.47      1.17
218971.2      0.00      0.00  217123.1      0.94      2.34
217754.7      0.00      0.00  215677.2      0.94      1.17
215763.1      0.00      0.00  214578.5      0.47      1.17
217850.3      0.00      0.00  216138.7      1.40      2.34
217668.0      0.00      0.00  215888.3      0.47      1.17
        em0                 em1                 bge1
  Kbps in  Kbps out   Kbps in  Kbps out   Kbps in  Kbps out
217382.3      0.00      0.00  216293.8      1.26      1.59
218247.9  118916.5  234167.3  124972.1      0.47      2.17
215973.4  220459.9  393350.0  54875.64      1.40      2.34
217697.7  210984.5  398543.3  58165.20      0.94      3.09
217183.6  200424.9  399096.5  61845.74      0.94      1.17
217788.7  221212.9  400129.8  53716.38      0.47      1.17
217040.0  204934.2  396628.7  61247.34      1.40      2.34
217105.9  201295.5  399274.1  61710.76      0.94      3.09
215605.6  225012.4  397533.5  53237.31      0.94      1.17
217933.3  200346.4  395949.3  62734.52      0.47      1.17
216783.7  205114.1  395923.0  61042.17      0.94      1.17
217885.7  88513.41  159056.4  151418.9      0.47      1.17
216927.2      0.00      0.00  215450.4      0.94      1.17
217454.1      0.00      0.00  215466.6      0.47      1.17
216810.6      0.00      0.00  215564.2      1.40      1.17
217608.3      0.00      0.00  216061.8      0.47      1.17
217452.8      0.00      0.00  215627.1      0.94      1.17
217185.0      0.00      0.00  216079.7      0.47      1.17


However, if I turn on fastforwarding, its back to the old behavior 
with it locking up.  This was with the stock driver. I will try the 
same test with

#define EM_FAST_INTR 1

as well as taking out the nfs option from the kernel 
driver.  Anything else to tune with ?

         ---Mike





>Scott