Hi Guys, Has anyone got a chance to look into this? Any clues?
Thanks, Rajesh. On Mon, Sep 7, 2020 at 11:33 PM Rajesh Kumar <rajf...@gmail.com> wrote: > Hi Michael, > > We use Interrupts for Rx packets. Whereas we poll for the link status. > > Thanks, > Rajesh. > > On Mon, Sep 7, 2020 at 11:17 PM Michael Sierchio <ku...@tenebras.com> > wrote: > >> Are you using device polling or interrupts on the interface? >> >> On Mon, Sep 7, 2020 at 10:40 AM Rajesh Kumar <rajf...@gmail.com> wrote: >> >>> Hi FreeBSD team, >>> >>> I am writing a network driver using the iflib framework and using the >>> "iperf" tool for performance testing. >>> >>> 1) 10G link with 9000 MTU: Seeing line-rate numbers on both Tx and Rx >>> path. >>> 2) 10G link with 1500 MTU. Seeing line-rate numbers on Tx path, but low >>> numbers on Rx path. >>> >>> Base issue seems to be that Rx buffers are not getting re-filled fast >>> enough. With low thread count, I see higher CPU utilization and lower >>> throughput. But with a higher number of threads, I could see better >>> throughput and lesser cpu utilization. >>> >>> iperf with 1 Thread: CPU Utilization is 80% - 95% - Throughput is ~4Gbps. >>> iperf with 2 Thread: CPU Utilization is 80% - 90% - Throughput is >>> ~7.5Gbps. >>> iperf with 4 Thread: CPU Utilization is 40% - 75% - Throughput is ~9Gbps. >>> iperf with 8 Thread: CPU Utilization is 30% - 70% - Throughput is >>> ~9.2Gbps. >>> >>> So, something is causing CPU utilization higher with lesser thread, which >>> kind of leads to Rx buffers not getting filled up faster and hence the >>> performance numbers drop. From a code perspective, I couldn't see any >>> evident CPU consuming operations in the Rx path. It's plain hardware >>> descriptors reading/processing. >>> >>> Anyway we can debug to find what is causing more CPU utilization (with >>> lesser threads) in my case? Any clues on debugging this issue? >>> >>> Thanks, >>> Rajesh. >>> _______________________________________________ >>> 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" >>> >> >> >> -- >> >> "Well," Brahmā said, "even after ten thousand explanations, a fool is no >> wiser, but an intelligent person requires only two thousand five hundred." >> >> - The Mahābhārata >> > _______________________________________________ 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"
