On Fri, 31 Mar 2017 18:55:45 +0200 (CEST), karl@xxxxxxxxxxx wrote: >I don't think most people have done testing that, and since I'm no pro. >in the audio field, I havn't tested that either. Personally I don't >believe that CONFIG_HZ matter at all. CONFIG_HZ is about the kernel >ordinary scheduling, the RT patch in some ways throws that away, so >why should CONFIG_HZ matter. > >Now the question is how instrument a test to verify that and what do >we want to measure ? There's no need for measurements. If you want to compare system timer 300 Hz with system timer 1000 Hz you e.g. could check if one or the other increases MIDI jitter by using https://github.com/koppi/alsa-midi-latency-test , but since by default usually hpet (hrtimer) is used, it doesn't matter. The question is, if for some reason hpet (hrtimer) shouldn't be used on some machines or by some software. There are also the tickless options. [rocketmouse@archlinux ~]$ cat /sys/devices/system/clocksource/clocksource0/available_clocksource tsc hpet acpi_pm [rocketmouse@archlinux ~]$ cat /sys/devices/system/clocksource/clocksource0/current_clocksource tsc [rocketmouse@archlinux ~]$ zgrep NO_HZ /proc/config.gz CONFIG_NO_HZ_COMMON=y CONFIG_NO_HZ_IDLE=y # CONFIG_NO_HZ_FULL is not set # CONFIG_NO_HZ is not set Btw. in the past, with my old mobo, Qtractor displayed using hrtimer and it was selectable by the list of sources. Now it displays "default" and doesn't offer hrtimer in the list. Any explanation for this is welcome. Regards, Ralf -- "Michael" described Floyd as "an idiot savant", and added, "Give him any two numbers, and he can multiply them in his head, just like that." Homer, testing Floyd, said, "Five times nine", and Floyd instantly responded "Forty-five", which impressed Homer. _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
