I cannot find SCHED_NO_HZ_FULL in v5.18: https://elixir.bootlin.com/linux/latest/A/ident/SCHED_NO_HZ_FULL
Could you elaborate? Thanks and best regards, Carsten On 24.06.22 17:01, Stephen Hemminger wrote:
On Thu, 23 Jun 2022 21:03:49 +0200 Carsten Andrich <carsten.andr...@tu-ilmenau.de> wrote:2. Use real-time priority (SCHED_FIFO w/ priority 99) for the DPDK threads and echo -1 > /proc/sys/kernel/sched_rt_runtime_us to disable the runtime limit. With the runtime limit in place, the SCHED_FIFO performance will be significantly worse than SCHED_OTHER.This can cause major issues if application is normal DPDK application (never does system calls). If an interrupt or other event happens on your isolated CPU, the work that it would do in soft irq is never performed. FIFO has higher priority than kernel threads. This can lead to mystery lockups from other applications (reads not completing, network timeouts, etc). In any semi-recent kernel using SCHED_NO_HZ_FULL will keep clock ticks from happening on the isolated cores.
