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Results of latency test, list of computers tested for use with LinuxCNC

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6 years 1 month ago #184136 by seuchato
Replied by seuchato on topic Results of latency test, list of computers tested for use with LinuxCNC

BeagleBrainz wrote: You could also add the modules to a blacklist, which is the usual way.


The thing is the kernel is detecting the sound card and the loading of the modules is not an error.
what does

Code:
dmesg | grep -i sound
output ?


just before invoking lcnc-hw:
Code:
dmesg | grep -i sound root@cnc0:~# uname -r 4.19.106-rt44-lcnc

now, while lcnc-hw is running:
Code:
lsmod | grep snd snd_pcsp 16384 3 snd_pcm 98304 2 snd_pcsp snd_timer 32768 1 snd_pcm snd 81920 8 snd_timer,snd_pcsp,snd_pcm soundcore 16384 1 snd

and I can hear the same garbled audio output. This seems rather weird to me! Il have to check on stock kernels as well, but with these there was never any audio output.
I cannot see a part in my script, that could invoke loading of these "snd" modules. Can only be firefox. But then why not on other kernels?

greez
chris

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6 years 1 month ago #184138 by BeagleBrainz
Replied by BeagleBrainz on topic Results of latency test, list of computers tested for use with LinuxCNC
There should be some activity logged in via dmesg after the modules load.

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6 years 1 month ago #184140 by seuchato
Replied by seuchato on topic Results of latency test, list of computers tested for use with LinuxCNC
Code:
lsmod | grep snd snd_pcsp 16384 2 snd_pcm 98304 1 snd_pcsp snd_timer 32768 1 snd_pcm snd 81920 7 snd_timer,snd_pcsp,snd_pcm soundcore 16384 1 snd root@cnc0:/home/cnc/lcnc-hw# dmesg | grep -i pcm root@cnc0:/home/cnc/lcnc-hw# dmesg | grep -i snd root@cnc0:/home/cnc/lcnc-hw# dmesg | grep -i sound

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6 years 1 month ago #184147 by BeagleBrainz
Replied by BeagleBrainz on topic Results of latency test, list of computers tested for use with LinuxCNC
Post
forum.linuxcnc.org/18-computer/39371-res...cnc?start=100#184136

and Post
forum.linuxcnc.org/18-computer/39371-res...cnc?start=100#184140

Seem to have differences in the used by column.
So apart from the snd modules being load what else is being loaded that wasn't loaded befroe ?

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6 years 1 month ago #184161 by seuchato
Replied by seuchato on topic Results of latency test, list of computers tested for use with LinuxCNC
I will reboot, then do
Code:
lsmod > pre
then start lcnc-hw, after say 30 secs Il do
Code:
lsmod > run
then after the script has terminated, il do
Code:
lsmod > post

Like that, we get diffs from pre/run/post. Hopefully that will help. Any other Idea?
Need to attend a meeting now, will do that later

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6 years 1 month ago #184172 by seuchato
Replied by seuchato on topic Results of latency test, list of computers tested for use with LinuxCNC
Ran lcnc-hw again now. here are the results:
Code:
uname -r 4.19.106-rt44-lcnc root@cnc0:/home/cnc/lcnc-hw# dmesg | grep -Ei "sound|snd|pcm" root@cnc0:/home/cnc/lcnc-hw# cat *.hw | grep -E "4\.19\.|secs" Kernel 4.19.106-rt44-lcnc 26 secs base min: -49.200 uS max: 53.300 uS sdev: 1.500 uS 26 secs servo min: -8.800 uS max: 7.600 uS sdev: 1.200 uS

Got a real time delay when running with basethread with 50'000 uS period. It is now running again without a basethread.

Here is the result with just a servo thread: I guess not bad at all for servo. But I'd like to use it with my existing 2 BOBs for a bridge mill and a lathe.
Code:
LinuxCNC pc tests, version 20200930, started 28.09.2020 13:57:58 ******************************************************************************** General info: Dell Inc., OptiPlex 980 Bios version A18, dated 02/27/2018 ... ================================================================================ Kernel related data: Kernel 4.19.106-rt44-lcnc GRUB_CMDLINE_LINUX_DEFAULT="quiet" Cpu idle driver: intel_idle ================================================================================ Kernel modules data: Check if pcspkr is loaded: No, which is good! Check if snd modules are loaded: No, which is good! ... ================================================================================ last latency data is as follows:. 7200 secs servo min: -45.100 uS max: 47.700 uS sdev: 2.900 uS 7201 secs servo min: -45.100 uS max: 47.700 uS sdev: 2.900 uS

Going to check the modules story now.

Greez
chris

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