[mythtv-users] rPi3 ram consumption causing playback freezing

[Peter Bennett]

On 07/15/2017 01:15 PM, Tim Draper wrote:
> i've had my rpi3 for a few weeks now and on the whole, it's been next to perfect.
>
> recently, i've found that playback can sometimes be extremely laggy so i initially went with a nightly reboot to freshen everything up. this sorted things getting out of hand over a few days.
> however i think i've now found that if i play something in the morning/over lunch, then come dinner time the playback will be laggy.
>
> 'htop' is showing ~85% general usage, ~1% buffer, and the remaining ~14% as buffer cache.... which brings total ram consumption to completely maxed out @ 100%.
>
> clearing the pagecache sorted the problem out with the following command without a reboot being required:
> sync; echo 1 > /proc/sys/vm/drop_caches
>
>
> the rpi config i use is as follows:
> rasbian latest & fully updated, mythtv-light used as per wiki.
> gpu_mem=192 (so 796MB remaining for the system)
> vm.swappiness=10
> MythFE theme: MythCenter-wide
> rpi3 gets left on 24/7 and playback is stopped when not using it  (going back to either recorded tv/main menu)
>
> what'd be the best way to sort this problem out? is there something i can tweak to properly stop it happening in the first place, or will running cron with the drop_caches cmd be the way forward?
>
> thanks..
>
> _______________________________________________
>
Did you look at the recommendations in the wiki
https://www.mythtv.org/wiki/Raspberry_Pi#System_Performance
In particular, item 1, setting the raspberry pi into performance mode, 
has to be run after each reboot, or before starting the frontend. 
Otherwise, the raspberry pi goes into a "power saving" mode where it 
slows down the CPU and causes the type of issue you describe.

Peter