On 07/11/2014 03:32 PM, Navdeep Parhar wrote: > On 07/11/14 10:28, John Jasem wrote: >> In testing two Chelsio T580-CR dual port cards with FreeBSD 10-STABLE, >> I've been able to use a collection of clients to generate approximately >> 1.5-1.6 million TCP packets per second sustained, and routinely hit >> 10GB/s, both measured by netstat -d -b -w1 -W (I usually use -h for the >> quick read, accepting the loss of granularity). > When forwarding, the pps rate is often more interesting, and almost > always the limiting factor, as compared to the total amount of data > being passed around. 10GB at this pps probably means 9000 MTU. Try > with 1500 too if possible.
Yes, I am generally more interested/concerned with the pps. Using 1500-sized packets, I've seen around 2 million pps. I'll have hard numbers for the list, with netstat and vmstat output Monday. <snip> >> a) One of the first things I did in prior testing was to turn >> hyperthreading off. I presume this is still prudent, as HT doesn't help >> with interrupt handling? > It is always worthwhile to try your workload with and without > hyperthreading. Testing Mellanox cards, HT was severely detrimental. However, in almost every case so far, Mellanox and Chelsio have resulted in opposite conclusions (cpufreq, net.isr.*). >> c) the defaults for the cxgbe driver appear to be 8 rx queues, and N tx >> queues, with N being the number of CPUs detected. For a system running >> multiple cards, routing or firewalling, does this make sense, or would >> balancing tx and rx be more ideal? And would reducing queues per card >> based on NUMBER-CPUS and NUM-CHELSIO-PORTS make sense at all? > The defaults are nrxq = min(8, ncores) and ntxq = min(16, ncores). The > man page mentions this. The reason for 8 vs. 16 is that tx queues are > "cheaper" as they don't have to be backed by rx buffers. It only needs > some memory for the tx descriptor ring and some hardware resources. > > It appears that your system has >= 16 cores. For forwarding it probably > makes sense to have nrxq = ntxq. If you're left with 8 or fewer cores > after disabling hyperthreading you'll automatically get 8 rx and tx > queues. Otherwise you'll have to fiddle with the hw.cxgbe.nrxq10g and > ntxq10g tunables (documented in the man page). I promise I did look through the man page before posting. :) This is actually a 12 core box with HT turned off. Mining the cxl stat entries in sysctl, it appears that the queues per port are reasonably well balanced, so I may be concerned over nothing. <snip> >> g) Are there other settings I should be looking at, that may squeeze out >> a few more packets? > The pps rates that you've observed are within the chip's hardware limits > by at least an order of magnitude. Tuning the kernel rather than the > driver may be the best bang for your buck. If I am missing obvious configurations for kernel tuning in this regard, it would not the be the first time. Thanks again! -- John Jasen (jja...@gmail.com) _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
