[mythtv-users] mythtv causing 100% CPU and 75 % memory load since last upgrade

[Johannes Rohr]

Am 06.02.2017 um 04:42 schrieb Peter Bennett:

> Do you compile your own MythTV for Arch Linux on Raspberry pi?

No, I just did the usual package upgrade: pacman -Suy
>
> Since I have no experience with a backend on raspberry pi, I do not
> know what the normal performance may be. How much CPU time was it
> using before? Maybe it was using 90% before and now is using 100%?
> Using 75% of memory also may not be unusual, since the Raspberry Pi
> only has 1 GB of main memory.

Until yesterday, it worked just fine. And when no client is connected,
mythbackend did not cause any CPU load most of the time, and when a
client connected, it wasn't that bad either. Now the behaviour, as I
wrote is that it only very very slowly responds to the client and then
dumps core.
>
> Maybe the new version of Arch Linux is 64bit and the old version was
> 32bit?

No. Again, I just did the normal package upgrade. Also, as I wrote above
I downgraded the package to an earlier version again, but to no avail.

>
> How do you connect tuners to the raspberry pi,
A hauppage WinTV usb stick, which I have been successfully using for
years with this device,

> and what do you do for storage?
A WD Elements external USB disk, 3 TB, with its own power supply. Again,
this has been in use for appr. 12 months without any problems.
>
> One thing I have noticed is, if you run a frontend on a raspberry pi
> with a hard drive attached, it seems to spend a lot of time scanning
> the hard drive. It works better with only an SD card. There may be
> some issues like this with a backend.

Well, again, the issues started only yesterday. It worked fine until the
day before.


I just wonder does anyone have a tip on how to investigate what
mythbackend is spending all the CPU time on? I already tried with a
fresh, empty database, the result was the same. Also, I did not find
obvious issues running strace on the process, and there is nothing in
the syslog.

Johannes

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