Date: Mon, 8 Aug 2016 16:01:20 +0200 From: Ben RUBSON <ben.rubson@gmail.com> To: freebsd-net@freebsd.org Subject: Re: Unstable local network throughput Message-ID: <BD0B68D1-CDCD-4E09-AF22-34318B6CEAA7@gmail.com> In-Reply-To: <5D6DF8EA-D9AA-4617-8561-2D7E22A738C3@gmail.com> References: <3C0D892F-2BE8-4650-B9FC-93C8EE0443E1@gmail.com> <bed13ae3-0b8f-b1af-7418-7bf1b9fc74bc@selasky.org> <3B164B7B-CBFB-4518-B57D-A96EABB71647@gmail.com> <5D6DF8EA-D9AA-4617-8561-2D7E22A738C3@gmail.com>
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> On 04 Aug 2016, at 11:40, Ben RUBSON <ben.rubson@gmail.com> wrote: >=20 >=20 >> On 02 Aug 2016, at 22:11, Ben RUBSON <ben.rubson@gmail.com> wrote: >>=20 >>> On 02 Aug 2016, at 21:35, Hans Petter Selasky <hps@selasky.org> = wrote: >>>=20 >>> 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. >>=20 >> My CPUs : 2x E5-2620v3 with DDR4@1866. >=20 > 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. >=20 > 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) OK, I then found a workaround. In the motherboards' BIOS, I disabled the following option : Advanced / ACPI Settings / NUMA And I'm now able to go up to 2x40Gb/s ! I'm then even able to achieve this throughput without any cpuset ! Strange that Linux was able to deal with this setting, but I'm pretty = sure production performance will be easier to maintain with only 1 NUMA. Feel free to ask me if you want further testing with 2 NUMA. Ben
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