designmule

On Sparky and Pi's "migration/0,1,2,3" all have RTPRIO of 99. On Sparky "irq/215-atc2603" has RTPRIO of 50 and "cfinteractive" has RTPRIO of 99 this is determined by entering the following ps ax --format uname,pid,ppid,tty,cmd,cls,pri,rtprio cfinteractive appears to be a CPU governor

I've made some progress on this. Revising the limits.conf file to 99 made no difference. The Pi's are also set at 100 and they work fine. Following a suggestion I found here: https://lists.opensuse.org/opensuse-security/2011-04/msg00015.html and here: https://unix.stackexchange.com/questions/114643/chrt-failed-to-set-pid-xxxs-policy-on-one-machine-but-not-others I tried the command sysctl -w kernel.sched_rt_runtime_us=-1 After running the command I am able to set and verify RT priorities using the CHRT command on the Sparky. However, a little research suggests that the command entered can make a system highly unstable as it can create a "runaway realtime priority". So I now know that my hardware and software do allow the realtime priority to be set but I have to find a safe way to do it.

I have modified /etc/security/limits.conf to give the audio group and my user real time priority. root - rtprio 100 @audio - rtprio 100 But I have not done anything in the limits.d folder. I'll be traveling for the next week and won't able to respond. I'll have to look into it further when I get back. Thanks for all of your suggestions.

Linux Sparky 3.10.38 #22 SMP PREEMPT Fri Dec 22 10:45:41 IST 2017 armv7l GNU/Linux

I am running dietpi 6.19.7 uid=0(root) gid=0(root) groups=0(root),29(audio) This matches the output on the pi's which are able to set rtprio

I'm still messing around with this. One odd thing I've noticed which may be related. I use putty to ssh into my dietpi machines from windows. When I ssh into the sparky (on which thread priorities are not working) in the upper left corner of putty the connection is listed as root@sparky (the hostname) when I ssh into the pi's the connection is just listed as the hostname though I sign in as root on all three. As I understand chrt and any rtprio are pretty locked down to non-root users. I wonder if somehow I managed to make my root account on the sparky not actually the root user. On the other hand both the sparky and the pi's all list the same users and entering sudo su on my sparky does not then allow me to set priorities via chrt. Thoughts?

I've figured out how JRiver was starting. There is an option in JRiver to set what runs on system startup. On my Pi's it was set to nothing but on my Sparky it was set to JRiver. Honestly, I didn't think that feature worked on JRiver's ARM version but once I turned it off, JRiver started via the JRiver service I created in systemd. Unfortunately, real time priorities are still not working. I get the same chrt operation not permitted error as before. This is the same with the clock set to hardware or emulated. I noticed however that I had a difficult time ssh'ing into the Sparky with hardware selected so I have reverted back to emultated. I noticed that on my Pi the cpu governor was set to ondemand while on the Sparky it was to performance. Changing it to ondemand made no difference. I tried updating firmware and that made no difference. Just to rule out JRiver, I tried setting another application to 99 via chrt and I got operation not permitted. I was able to set it successfully on a pi. I've posted over at the DietPi forum to see if anyone has some suggestions. It has to be some setting that got changed along the way. I'll report back if I hear anything or figure out how to fix it on my own. Thanks for the help Matt

find /etc -type f -exec grep -l mediacenter24 {} \; doesn't seem to do anything

apt-get install findutils returns: findutils is already the newest version (4.6.0+git+20161106-2). findutils set to manually installed. 0 upgraded, 0 newly installed, 0 to remove and 2 not upgraded. the subsequent find / -type f -exec grep -l mediacenter24 {} \; returns: find: ‘grep’ terminated by signal 11 grep: /proc/sysrq-trigger: Input/output error

The chrt -p 99 1447 was run on a pi which is handling thread priorities as intended. find / -type f -exec grep -l mediacenter24 {} \; returns "find: command not found" I also tried find ./-type f -exec grep -l 'mediacenter24' {} \; based on some tutorials and the results were the same.

Well, I made the change to dietpi-config, restarted and results are the same. I checked my pi (on which thread priorities is working) and RTC mode is set to Emulated. Is hardware always the better option? Should I change it on my pi? I'll have to look through the startup method for JRiver. That seems to be a point of differentiation between the sparky and the pi. The sparky was my first exposure to dietpi and the install is about a year old. The pi was switched from raspbian to dietpi a few weeks ago. I might have made some mistakes setting up the sparky. I also wonder if it has something to do with the DAC being connected via the USB Bridge. Are you running a USB DAC connected to the USB Bridge? I really do appreciate all of your help. Matt

I rebooted the Sparky and again entered ps -ef | grep mediacenter24 and it returned the following values root 2413 1 0 18:33 tty1 00:00:00 sh -c sleep 5; /usr/bin/mediacenter24 root 2557 2413 16 18:33 tty1 00:01:20 /usr/bin/mediacenter24 root 3957 3764 0 18:41 pts/0 00:00:00 grep --color=auto mediacenter24 chrt -p 99 2557 returns: chrt: failed to set pid 2557's policy: Operation not permitted Your comment about started via double click is interesting because that is not how I start JRiver...I don't double click it anyway. I believed that it started via the jriver.service. However, ps -ef | grep mediacenter24 entered on one of my Pi's (which run dietpi as well and on which thread priorities are working via the JRiver method) returns: root 1447 1 4 Dec10 ? 00:53:59 /usr/bin/mediacenter24 /MediaServer root 4016 3865 0 18:42 pts/0 00:00:00 grep mediacenter24 No tty1 present. chrt -p 99 1447 does not return an error. It looks like I need to look into how JRiver is being started on the sparky I thought that I had them all setup the same way, that's my goal anyways but apparently I don't. I really appreciate all your help. I think I'm getting close I just need to revisit some of my configuration. Matt

ps -ef | grep mediacenter24 returns: root 2408 1 0 23:12 tty1 00:00:00 sh -c sleep 5; /usr/bin/mediacenter24 root 2545 2408 7 23:12 tty1 00:00:26 /usr/bin/mediacenter24 root 3753 3561 0 23:18 pts/0 00:00:00 grep --color=auto mediacenter24 I'm not sure which of these is the pid and if I had to guess there are multiple pids. Sorry, I'm a bit "over my skis" here. I appreciate the help.

I appreciate the help but no dice. At least via the command the JRiver folks suggest will verify thread priorities are working, I get no suggestion that they are. ps -T -eo pid,tid,class,rtprio,ni,pri,comm | grep mediacenter24 I'll keep investigating. I'd like to try your modification to one of my Raspberry Pis (which handle thread priorities correctly according to the JRiver tutorial) to establish if it is a Sparky thing, a dietpi thing or maybe a typo thing. I appreciate the suggestions. Matt

I appreciate the advice. Thanks!