[mythtv-users] random livetv stalls

[Raymond Wagner]

On 2/10/2014 11:05 PM, Kevin Johnson wrote:
> Seems I have further improved the system by reducing the hd ringbuffer
> size on the backend down to the min of 4700.
> I had it set much higher at around 37000.  Cant remember why i had
> altered it.
> I still get a pause at the top and bottom of the hour, but only about 1
> second or less.

The "HD Ringbuffer" is basically just a first stage byte array into 
which data directly from the hardware capture device is written, running 
in a tight loop to prevent the hardware buffers from filling and 
dropping data. Recording data is only held there briefly before being 
processed and handed off to the file writer. The buffer defaults to 
around 9MB if unset, and under normal conditions, that buffer should 
remain nearly empty. The only time it should fill up is if the system is 
severely starved of CPU.

If you're actually seeing a meaningful change in performance by 
manipulating that setting, and it's not just digging into swap because 
of an extra 30MB of memory used per recorder, is there any chance of 
getting you to recompile with -DREPORT_RING_STATS?