--- [EMAIL PROTECTED] wrote:

>     Date: Wed, 24 Jan 2007 13:17:11 +0100 (CET)
>     From: "Hans Verkuil" <[EMAIL PROTECTED]>
> 
>     > > I've started playing with that query but it's already fairly
> optimized.
>     > > It
>     > > seems to me that the only real solution is to put the database on
> another
>     > > machine with a whole lot of RAM.  Right now I'm up to one backend
> which
>     > > has
>     > > two PVR-150s for recording, one backend/frontend with a PVR-350 for
>     > > viewing
>     > > and recording, one backend which has no encoders for storage only,
> one
>     > > backend/frontend which as the master backend.
>     > >
>     > > I thought that isolating each of the jobs would help, but even on the
>     > > latest
>     > > trunk with enc_mpg_buffers=16 I'm still getting the:
> 
>     > Just verifying that I understand it correctly: this also happens with a
>     > non-trunk ivtv release, correct? So it is not some ivtv trunk bug that
> is
>     > hiding somehwere.
> 
> It's been happening to me all the way back in ivtv 0.4.1 (see other
> traffic of mine today).  I'm convinced this is a myth bug related to
> stalling the emptying of ivtv buffers while the process responsible
> for that waits on a MySQL lock held by the myth scheduler.
> 

I should mention that I'm using ivtv-svn on a 266MHz ARM cpu with 64MB memory
and I can keep up just find streaming a 4mbps stream from a cx23416.  So... I
would have to agree that the issues this thread is talking about must be
something in mythtv thats causing it to not pull data fast enough.

Tim

>     > > Jan 23 23:00:26 mythcorder kernel: ivtv1: All encoder MPEG stream
> buffers
>     > > are full. Dropping data.
>     > > Jan 23 23:00:26 mythcorder kernel: ivtv1: Cause: the application is
> not
>     > > reading fast enough.
>     > > Jan 23 23:00:26 mythcorder kernel: ivtv1: All encoder MPEG stream
> buffers
>     > > are full. Dropping data.
>     > > Jan 23 23:00:26 mythcorder kernel: ivtv1: Cause: the application is
> not
>     > > reading fast enough.
>     > > Jan 23 23:00:26 mythcorder kernel: ivtv1: All encoder MPEG stream
> buffers
>     > > are full. Dropping data.
>     > > Jan 23 23:00:26 mythcorder kernel: ivtv1: Cause: the application is
> not
>     > > reading fast enough.
>     > > Jan 23 23:00:26 mythcorder kernel: ivtv1: All encoder MPEG stream
> buffers
>     > > are full. Dropping data.
>     > > Jan 23 23:00:26 mythcorder kernel: ivtv1: Cause: the application is
> not
>     > > reading fast enough.
>     > >
>     > > It happens on both boxes that do encoding, usually at the beginning
> of the
>     > > recording, but sometimes you'll be watching a recording and it will
> have
>     > > done it halfway through.  It's the worst when you miss the build-up
> to a
>     > > joke and you only catch the punchline.
> 
> I'm betting that the "beginning" issues are because you had some other
> program that ended just then---which caused the scheduler to run.  The
> "halfway through" is probably because a you're recording one show from
> 1pm to 2pm and another show ends at 1:30pm---causing a scheduler run.
> 
> I'm also betting you'll see this if you -delete- something while
> recording, because deletions cause scheduler runs.
> 
> (All of my recordings start/end 1-2m early/late, so I very frequently
> get a glitch a minute or two into a recording because other one just
> ended at :01 or :02.)
> 
>     > With 16 MB of buffers that should give you somewhere between 10-16
> seconds
>     > of buffering I think. I find it hard to believe that MythTV would take
> so
>     > much time! You can easily check how full the various buffers are by
>     > running v4l2-ctl --log-status.
> 
> My MythTV scheduler queries take 15-25 seconds.  Thus, I frequently
> run out of buffers.  Others have responded likewise.  (There's also
> traffic in the last few hours on the myth dev list indicating that
> certain types of schedules can make the problem worse, and fixing
> -all- of them can bring down the time by a factor of 4 or so---but
> asking random end users to correctly predict myth's scheduler
> performance is really asking way too much of them, I'd wager.)
> 
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> 


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