Proposed 6.2 em RELEASE patch

[Scott Long]

Mike Tancsa wrote:
> At 08:19 PM 11/8/2006, Jack Vogel wrote:
> 
>> BUT, I've added the FAST_INTR changes back into the code, so
>> if you go into your Makefile and add -DEM_FAST_INTR you will
>> then get the taskqueue stuff.
> 
> It certainly does make a difference performance wise.  I did some quick 
> testing with netperf and netrate.  Back to back boxes, using an AMD x2 
> with bge nic and one intel box
> 
> CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ (2009.27-MHz 
> 686-class CPU)
> CPU: Intel(R) Core(TM)2 CPU          6400  @ 2.13GHz (2144.01-MHz 
> 686-class CPU)
> 
> The intel is a  DG965SS with integrated em nic, the AMD a Tyan with 
> integrated bge.  Both running SMP kernels with pf built in, no inet6.
> 
> 
> Intel box as sender. In this test its with the patch from yesterday. The 
> first set with the patch as is, the second test with -DEM_FAST_INTR.
> 

Thanks for the tests.  One thing to note is that Gleb reported a higher
rate of dropped packets with INTR_FAST.  He is the only one who has
reported this, so I'd like to find out if there is something unique to
his environment, or if there is a larger problem to be addressed.  There
are ways that we can change the driver to not drop any packets at all
for Gleb, but they expose the system to risk if there is ever an
accidental (or malicious) RX flood on the interface.

Scott