pá 6. 12. 2024 v 12:52 odesílatel Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> napsal: > What is the default behaviour and what is the intended behaviour? > Couldn't we somehow avoid adding yet another option? The default behavior is to hold /dev/cpu_dma_latency at zero, which disables all idle states on all CPUs, not only those on which cyclictest measurements are running. This has the disadvantage of a higher power consumption than needed in most cases. With --deepest-idle-state, idle states are limited only on CPUs cyclictest is running on. There are two reasons why we can't just use the latter and have to have options for both. Firstly, some hardware does not support disabling idle states on individual CPUs via the cpuidle sysfs interface, which is used by --deepest-idle-state. Secondly, latencies measured with --deepest-idle-state might still be higher in some cases compared to holding /dev/cpu_dma_latency. > > > I suggest deferring this to a future patch that would remove the > > warnings and another one to refactor the code. > > Sebastian > Tomas
