Hi all,
I'm running a DPDK transmit thread with the ixgbe PMD on Ubuntu 17.04, with
dual Xeon E5-2623 v4 CPUs on an Intel S2600 motherboard. The cores in use by
DPDK are isolated in the boot cmdline with "isolcpus"
What I'm observing is I believe, on occasion, the DPDK transmit thread being
descheduled by the system for between 20 and 60 milliseconds.
I've tried running as Real time with max priority, and tweaking the scheduling
through /proc/sys/kernel/sched_rt_runtime_us to be 99.999% available for real
time thread, but so far no improvement
I notice there are various kernel threads resident on the isolated cpus,
cpuhp/watchdog/migration/ksoftirqd +multiple kworker threads.
I can only assume the system is occasionally running these kernel side instead,
although the CPU time taken (tens of milliseconds) seems very high. Note
please that I amd NOT running with a modified kernel (nohz_full is not set).
Does anyone have any advice to keep the DPDK transmit thread running for more
of the time on this SMP system ?
Many thanks
Terry.
