Re: About rtla osnoise and timerlat usage

Prasad Pandit
2023-02-23T12:12:36Z

Hello Daniel,

On Thu, 23 Feb 2023 at 00:41, Prasad Pandit <ppandit@redhat.com> wrote:
> # trace-cmd record -p nop -e all -M 0x7FE -m 32000 --poll ~test/rt-tests/oslat --cpu-list 1-10 --duration 1h -w memmove -m 4K -T20
> ....
> Maximum: 14 11 13 12 12 13 12 11 12 10 (us)
> Max-Min: 13 10 12 11 11 12 11 10 11 9 (us)
> Duration: 3599.986 3599.986 3599.987 3599.987 3599.986 3599.987 3599.986 3599.987 3599.986 3599.986 (sec)
>
> * Running oslat(1) with SCHED_OTHER priority via 'trace-cmd --poll' option, did not show the spike. Nonetheless, trace-cmd(1) logs show <idle>, ktimers/ and kworker/ threads running on isolated CPUs.
> * Now running rtla-osnoise(1) test with SCHED_OTHER:
> # rtla osnoise top -c 1-10 -d 6h -s 20 -T 20 -Po:0 -q -t

Please see:
-> https://0bin.net/paste/ShXHmdvu#D0XY-WxTKCzWTxgQ+lTFbx1nB2TP2w+T0Mp8PBXt9gu

* rtla-osnoise(1) running for 6 hours with SCHED_OTHER and SCHED_FIFO,
both did not report any spike above 20us.
It's reporting occurrence of IRQs only, all other noise columns are
zero(0). That's a little surprising!?

Thank you.
---
- Prasad