I'm using a realtime-enabled kernel, and I noticed that when I do the command:
ps axo pid,nice,rtprio,comm
It does not print the nice value for a process if the process has a realtime value. If I "renice" a process that has a realtime value set, renice will give the old nice value as well as the new value being set, so I know that the nice value doesn't seem to be lost just by setting the realtime priority. Also, the correct nice value is also displayed in ksysguard for example.
So why doesn't the ps command above display the nice value for realtime prioritized processes?
I'm wondering if maybe the crucial question to ask first is--does the nice value matter if the process has a realtime priority? In other words, does a process with a realtime priority (even the lowest realtime priority) always take precedence over other processes that may have a nice value of -20 (highest nice priority)? Is that why the ps command above doesn't give a nice value for realtime prioritized processes? Thanks for any help.