[mythtv-users] Mythbuntu 8.10 and Realtime Priority

[James Crow]

On Thu, 2009-02-19 at 07:52 -0500, James Crow wrote:
<snip lots of good advice>
> 
> Last night I watched a few recordings with Myth. This morning when I
> looked through the logs I see that Myth thinks it is running with
> realtime priority. However when I view the processes with top it shows
> mythfrontend with nice 20 instead of RT. In this post
> http://www.gossamer-threads.com/lists/mythtv/users/370582#370582
> matthias mentions that even though realtime appears in the log the
> frontend may not be running with realtime priority. He suggests to use
> top or schedtool to verify. Can anyone give me more details on a way to
> tell if the frontend is using RT threads?
> 
> Thanks,
> James
> 

I installed schedtool on my machine and started a watching a recording.
Another user mentioned that maybe only the video thread would be RT
while the rest would be normal. While the FE was displaying a recorded
program I looked at the process in top and with schedtool here is what I
found:



top - 09:33:35 up 11:32,  3 users,  load average: 0.51, 0.39, 0.32
Tasks: 147 total,   1 running, 146 sleeping,   0 stopped,   0 zombie
Cpu(s): 21.9%us,  1.7%sy,  0.0%ni, 76.2%id,  0.0%wa,  0.0%hi,  0.2%si, 
Mem:   2056260k total,  2036160k used,    20100k free,    14032k buffer
Swap:  5654840k total,     5836k used,  5649004k free,  1414004k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND   
 8477 root      20   0  306m 193m  37m S   29  9.6   0:38.92 Xorg      
 8693 james     20   0  732m 222m  60m S   23 11.1   5:15.91 mythfronte
 8606 james     20   0  193m 6176 4288 S    1  0.3   0:00.22 gnome-scre
 8949 james     20   0 19100 1344  988 R    1  0.1   0:00.20 top       
    1 root      20   0  5232 2012  608 S    0  0.1   0:00.88 init      
    2 root      15  -5     0    0    0 S    0  0.0   0:00.00 kthreadd  
    3 root      RT  -5     0    0    0 S    0  0.0   0:00.00 migration/
    4 root      15  -5     0    0    0 S    0  0.0   0:00.22 ksoftirqd/
    5 root      RT  -5     0    0    0 S    0  0.0   0:00.00 watchdog/0
    6 root      RT  -5     0    0    0 S    0  0.0   0:00.00 migration/
    7 root      15  -5     0    0    0 S    0  0.0   0:03.48 ksoftirqd/
    8 root      RT  -5     0    0    0 S    0  0.0   0:00.00 watchdog/1
    9 root      15  -5     0    0    0 S    0  0.0   0:00.58 events/0  
   10 root      15  -5     0    0    0 S    0  0.0   0:00.48 events/1  
   11 root      15  -5     0    0    0 S    0  0.0   0:00.00 khelper   
   49 root      15  -5     0    0    0 S    0  0.0   0:00.00 kinteg



and schedtool:
$ schedtool 8693
PID  8693: PRIO   0, POLICY N: SCHED_NORMAL  , NICE   0, AFFINITY 0x3

I am still learning to interpret this information, but it appears that
the mythfrontend thread is running with normal scheduling.

Is there something I am missing from getting it to actually use RT
priority?

Thanks,
James