[ardour-dev] Ancient history? - Problem identified

R Parker rtp405 at yahoo.com
Thu Nov 11 22:38:56 PST 2004 

Hi Jan,

--- Jan Depner <eviltwin69 at cableone.net> wrote:

> Just curious but are you both running NVIDIA
> graphics cards with the
> accelerated driver?

I'm running an ATI Radeon 9500 Pro. I've tried the X
drivers and the drivers from ATI. I don't know if
either makes any difference. I'm running ATI drivers
now. I've tried all the suggestions I could find. I
don't even remeber what those things are something
about increasing air intake to the carbs and grinding
the stupid valves. Maybe I'll try moth balls in the
gas.

I used to have an old nvidia card and never had
problems with it. I should go back to that one.

At the moment, I've got 115 minutes at 1024 frames,
44100, 24bit with 16 record enabled tracks and while
checkin' mail, opening tabs and pages with mozilla,
chating on #ardour with zero xruns. This is on an IDE
drive.

Maybe most of the xruns I see these days are from
opening and closing applications that aren't realtime
safe and from Ardour Export functions.

ron

> Jan
> 
> On Thu, 2004-11-11 at 11:52, R Parker wrote:
> > Hi Joel,
> > 
> > --- cv223 at comcast.net wrote:
> > 
> > > A few days ago I posted the following message
> about
> > > tracking down xruns using Ardour to record to a
> SCSI
> > > Raid0.  At the end of the message, I asked
> whether
> > > anyone had any ideas about why commenting out a
> > > single line in streamview.cc (which at the very
> > > least eliminates updating the "progress"
> rectangles
> > > during recording) completely eliminates my xrun
> > > problem, in a rather dramatic fashion (dozens of
> > > xruns per min to none).  Since I got a goose egg
> in
> > > response, I thought I would try again because
> I've
> > > run out of things to test and don't know where
> to
> > > look next.  
> > 
> > I took note of your first message. It's certainly
> an
> > interesting discovery. 
> > 
> > > Basically, how can display updates in Ardour
> during
> > > recording cause xruns with writes to the hard
> > > drives?
> > 
> > I'm not a programmer but we have to imagine the
> > function operates outside the realtime threads. If
> > that's correct and all is well within the code,
> then
> > Ardour isn't the cause but does trigger the
> symptom.
> > 
> > It would seem to indicate xruns caused by the
> video
> > driver but you have narrowed it down to a hardware
> > scsi raid event where the problem occurs.
> > 
> > Being pretty clueless, perhaps all I'm doing is
> trying
> > to add some life to your thread. Incidentally, the
> > region drawing code was written by Jesse
> Chappel--I
> > think. If you do IRC, he can often be found on
> > freenode.net #ardour.
> > 
> > Sorry I can't be very helpful, more sorry than you
> > know because I also run hardware raid and have
> xrun
> > problems.
> > 
> > ron
> > 
> > > Since this problem doesn't seem to be common, it
> > > seems that it has more to do with my
> system/hardware
> > > configuration than with Ardour/jack.  But what,
> I
> > > don't know.
> > > 
> > > Any suggestions would be greatly appreciated. 
> > > Thanks for your time.
> > > 
> > > Joel
> > > -------------- Original message -------------- 
> > > 
> > > > (Note that I didn't write "Problem solved" - I
> > > don't know how to solve 
> > > > it, besides a hack described below) 
> > > > 
> > > > About a week ago, I posted a message asking
> about
> > > possible reasons why 
> > > > xruns seen using 0.9beta11.2 when recording to
> a
> > > SCSI Raid0 went away 
> > > > with 0.9beta12 (on a 2.4.23 kernel). Paul took
> > > pity on my poor, 
> > > > tormented soul and let me have cvs access
> (thanks
> > > again, Paul!) so I 
> > > > could try and track down the problem. I went
> > > through a number of old 
> > > > cvs versions by the dates of "CVS commit"
> messages
> > > to the ardour-dev 
> > > > list (not sequentially - I don't have _that_
> much
> > > time!) and found the 
> > > > smoking gun to be on May 7, 2004, when Jesse
> > > Chappell committed code to 
> > > > put waveforms into regions while recording.
> That
> > > code pointed out where 
> > > > the problem was. 
> > > > 
> > > > To make a long story somewhat shorter, it
> turns
> > > out that on my system, 
> > > > updating the regions during recording (even
> with
> > > "Follow playhead" 
> > > > turned off) generates xruns when the SCSI Raid
> is
> > > written to (i.e., 
> > > > xruns occur when the drives chirp).
> Specifically,
> > > if I comment out line 
> > > > 700 in streamview.cc (this is in routine
> > > StreamView::update_rec_box() 
> > > > in 0.9beta19): 
> > > > 
> > > > // gtk_canvas_item_set (rect, "x2", xend,
> NULL); 
> > > > 
> > > > and run Ardour with the Display Option "Show
> > > waveforms while recording" 
> > > > turned off, I get no (zero!) xruns while
> recording
> > > to the SCSI Raid, 
> > > > where before I got > 25 per 1 minute of
> recording.
> > > Of course, I don't 
> > > > get the pinkish boxes growing across the
> screen,
> > > but I can live with that. 
> > > > 
> > > > If I don't comment out that line, I get just
> as
> > > many xruns on the newer 
> > > > versions of Ardour as before - I hadn't tried
> > > turning "Show 
> > > > waveforms..." off before I started on my cvs
> > > quest. I guess I thought 
> > > > the waveforms during recording were too cool. 
> > > > 
> > > > Turning on the "Show waveforms..." still
> generates
> > > about 3 xruns per 
> > > > minute of recording, so I still don't know
> what's
> > > going on there (other 
> > > > gtk canvas access, perhaps?). Also, running
> under
> > > the 
> > > > 2.6.9-rc2-mm4-VP-S7 kernel still generates a
> > > handful of xruns per minute 
> > > > on either Raid or IDE drives even with the
> above
> > > hack, so something 
> > > > different still seems to be happening with
> that
> > > kernel. I'll stick with 
> > > > 2.4.23 for now. 
> > > > 
> > > > If anybody has any ideas about what may be
> going
> > > on (how gtk canvas 
> > > > access + SCSI Raid writes = xruns), I'm still
> > > curious. Also, I'm 
> > > > willing to try additional tests, if it would
> be
> > > helpful. 
> > > > 
> > > > BTW, this is with gtk+ version 1.2.10. 
> > > > 
> > > > Thanks for your time, 
> > > > 
> > > > Joel 
> > > > 
> > > > 
> > > > 
> > > >
> _______________________________________________ 
> > > > ardour-dev mailing list 
> > > > ardour-dev at lists.ardour.org 
> > > >
> > >
> >
>
http://lists.ardour.org/listinfo.cgi/ardour-dev-ardour.org
> > > _______________________________________________
> > > ardour-dev mailing list
> > > ardour-dev at lists.ardour.org
> > >
> >
>
http://lists.ardour.org/listinfo.cgi/ardour-dev-ardour.org
> > > 
> 
=== message truncated ===



		
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