[mythtv] Ticket #10414: HDHomeRun: Bad Recordings (was: Bad Recordings - Choppy Playback)

[Daniel Kristjansson]

On Fri, 2012-03-09 at 13:17 -0500, Tom Lichti wrote:
> On Fri, Mar 9, 2012 at 12:44 PM, Derek Atkins <warlord at mit.edu> wrote:
> > Tom Lichti <tom at redpepperracing.com> writes:
>
> I'm trying to rule that out. I don't think it's network or interrupts,
> I have all Gig-E networking, and the backend is actually a server,
> Dell Poweredge SC1435, so the only thing I can see is it being the
> disk. I'll try putting a storage group on another disk and test that
> and report back.

I doubt it is the disk. 0.25 dynamically resizes it's buffer up to
about 128 MB per recording vs the user specified buffer that defaulted
to 9.6MB in 0.24.

I was able to reproduce a problem with old firmware using udp
streaming, but with newer firmware employing rtp streaming I
can not reproduce the issue. I'm also not seeing the high CPU
usage reported. I see about 15% CPU usage with two recordings.

Can you take a look at this:
  http://www.cyberciti.biz/faq/linux-tcp-tuning/
And tell me if increasing the rmem_max helps?
libmythhdhomerun tries to increase the socket buffer
on startup, but perhaps the rmem_max is set low on
your system? Mine is set to 131071000.

-- Daniel