[mythtvnz] realtime scheduling of the backend?

[Steven Ellis]

On Mon, March 31, 2008 11:20 pm, Michael Dilger wrote:
> What is the best way to ensure that you don't get "Dropping data' from
> ivtv when your system gets busy?
>
> I use my MythTV server for a lot of things, mostly MythTV and an NFS
> storage server (from xfs).   Sometimes it gets busy (gentoo emerge
> compiling, me watching a video, maybe a compile on another computer
> fighting for the filesystem's time).. and the front end
> is also the same machine .... and when it gets busy I get these kernel
> messages:
>
> Mar 29 17:59:11 [kernel] ivtv0: All encoder MPEG stream buffers are
> full. Dropping data.
> Mar 29 17:59:11 [kernel] ivtv0: Cause: the application is not reading
> fast enough.
> Mar 29 17:59:38 [kernel] ivtv0: All encoder VBI stream buffers are full..
> Dropping data.
> Mar 29 17:59:38 [kernel] ivtv0: Cause: the application is not reading
> fast enough.
>
> When that happens, and I go check, the recorded video has a lot of
> drop-outs and skips.
>

Sounds like you need to tweak the VM settings. Try putting the following
in /etc/sysctl.conf

vm.min_free_kbytes=16384


Steve


--------------------------------------------
Steven Ellis - Technical Director
OpenMedia Limited - The Home of myPVR
email   - steven at openmedia.co.nz
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