> On 04 Aug 2016, at 17:33, Hans Petter Selasky <h...@selasky.org> wrote: > > On 08/04/16 17:24, Ben RUBSON wrote: >> >>> On 04 Aug 2016, at 11:40, Ben RUBSON <ben.rub...@gmail.com> wrote: >>> >>>> On 02 Aug 2016, at 22:11, Ben RUBSON <ben.rub...@gmail.com> wrote: >>>> >>>>> On 02 Aug 2016, at 21:35, Hans Petter Selasky <h...@selasky.org> wrote: >>>>> >>>>> The CX-3 driver doesn't bind the worker threads to specific CPU cores by >>>>> default, so if your CPU has more than one so-called numa, you'll end up >>>>> that the bottle-neck is the high-speed link between the CPU cores and not >>>>> the card. A quick and dirty workaround is to "cpuset" iperf and the >>>>> interrupt and taskqueue threads to specific CPU cores. >>>> >>>> My CPUs : 2x E5-2620v3 with DDR4@1866. >>> >>> OK, so I cpuset all Mellanox interrupts to one NUMA, as well as the iPerf >>> processes, and I'm able to reach max bandwidth. >>> Choosing the wrong NUMA (or both, or one for interrupts, the other one for >>> iPerf, etc...) totally kills throughput. >>> >>> However, full-duplex throughput is still limited, I can't manage to reach >>> 2x40Gb/s, throttle is at about 45Gb/s. >>> I tried many different cpuset layouts, but I never went above 45Gb/s. >>> (Linux allowed me to reach 2x40Gb/s so hardware is not a bottleneck) >>> >>>>> Are you using "options RSS" and "options PCBGROUP" in your kernel config? >>> >>> I will then give RSS a try. >> >> Without RSS : >> A ---> B : 40Gbps (unidirectional) >> A <--> B : 45Gbps (bidirectional) >> >> With RSS : >> A ---> B : 28Gbps (unidirectional) >> A <--> B : 28Gbps (bidirectional) >> >> Sounds like RSS does not help :/ >> >> Why, without RSS, do I have difficulties to reach 2x40Gbps (full-duplex) ? >> > > Hi, > > Possibly because the packets are arriving at the wrong CPU compared to what > RSS expects. Then RSS will invoke a taskqueue to process the packets on the > correct CPU, if I'm not mistaken.
But even without RSS, I should be able to go up to 2x40Gbps, don't you think so ? Nobody already did this ? _______________________________________________ freebsd-net@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
