* Mike Silbersack <[EMAIL PROTECTED]> [011012 01:30] wrote: > > Well, I've been watching everyone argue about the value of interrupt > coalescing in the net drivers, so I decided to port terry's patch to 4.4 & > -current to see what the results are. The patch included applies cleanly > to 4.4's if_dc, and will apply to -current with a one line change. > Whitespace is horrible, I copied and pasted the original patch, used patch > -l, etc. > > The test setup I used was as follows: > Duron 600, PNIC, running -current > Celeron 450, ADMtek tulip-clone, running -stable > > The network is 100mbps, switched. To simulate load, I used a syn flooder > aimed at an unused port. icmp/rst response limiting was enabled.
Actually, you might want to leave that on, it will generate more load. > > With the -current box attacking the -stable box, I was able to notice a > slight drop in interrupts/second with the patch applied. The number of > packets was ~57000/second. > > Before: ~46000 ints/sec, 57-63% processor usage due to interrupts. > After: ~38000 ints/sec, 50-60% processor usage due to interrupts. > > In both cases, the box felt responsive. You need to get real hardware to run these tests, obviously you aren't saturating your line. I would suspect a better test would be to see how many pps you get can at the point where cpu utlization reaches 100%. Basically start at a base of 60,000pps, and see how many more it takes to drive them both to 100%. Even your limited tests show a mean improvement of something like 10%. 10% isn't earth shattering, but it is a signifigant improvement. -Alfred To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
