30 Jul
2018
30 Jul
'18
11:58 p.m.
On 07/30/2018 12:49 PM, Ralf Mardorf wrote:
Hi,
by View > Options... > MIDI tab I can chose between 'default',
'system timer' (for my current installed rt kernels 300Hz), 'HR timer'
and diverse 'PCM' timers. My old computer doesn't have 'TSC', so
Qtractor's queue timer still is set to use 'HR timer', to reduce MIDI
jitter. If I want to chose 'TSC', when running Qtractor on my new
machine, should there be an entry 'TSC' or since it's the current
clocksource, would selecting 'default' be the option to use 'TSC'? IOW
what is 'default' for and why is there no option to select 'TSC'?
[rocketmouse@archlinux ~]$ cat /sys/devices/system/clocksource/*/available_clocksource
tsc hpet acpi_pm
[rocketmouse@archlinux ~]$ cat
/sys/devices/system/clocksource/clocksource0/current_clocksource
tsc
[rocketmouse@archlinux ~]$ qtractor -v
qt5ct: using qt5ct plugin
Qt: 5.11.1
Qtractor: 0.9.1
those are low-level, read kernel time/clock sources.
instead, the timers that qtractor may use are the high-level ones that
are available through ALSA and only; hrtimer is often the default one
iif the kernel is configured to CONFIG_SND_SEQ_HRTIMER_DEFAULT=y.
you can always check all the available ALSA timers from:
/proc/asound/timers
the effective current timer in use is listed there, as soon you activate
an ALSA seq queue (eg. qtractor):
/proc/asound/seq/timer
hth.
cheers
--
rncbc aka. Rui Nuno Capela