On 2024-10-24 09:24, Felix Moessbauer wrote:
the ntpsec service starts the ntpd binary with the option "-N|--nice" (defined in ntpsec.default (/etc/default/ntpsec) [1]. By that, the ntpd will run with the highest possible priority, which is SCHED_FIFO, prio 99. These priorities are discouraged as this can starve kernel threads. I also don't think that it is the intention of the maintainer to let it run at such a high priority.
It actually was my intention. Perhaps that was misguided. But as I understood that option, it would prioritize ntpd. Maybe that's not actually necessary for good timekeeping, though? I've asked on the NTPsec devel list. Perhaps someone there can provide more insight.
Some recent stalls of PREEMPT_RT systems we observed could be related to this.
Do you have any follow-up on this? If that "could be" was upgraded to a "were", then it would be a much stronger case for removing this flag.
-- Richard
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