[mythtv-users] 0.20 high cpu usage - suggestions?

[rob+myth at robnet.com]

Hello all.  I would really appreciate some pointers or advice on what to do
next to get my myth box recording again.  The short story is that 0.19 worked
fine on this hardware.  Since the 0.20 upgrade I've had some trouble with
occational high cpu while recording, resulting in damaged recordings.  Thanks
to this list and google I've made some progress, mostly eliminating possible
problems... and now it's no longer an occational problem, it always happens.
That's progress... right?  :)  I assume I was having some other problem
originally (probably the 480x480 vbi problem), and now I have a new problem...

Some 30 seconds or less after starting a recording the %cpu for mythbackend
climbs to 100% +/-, and I get the "dropping data" messages from ivtv (full
message below).  No message in mythbackend.log, but I need to run again with
more logging enabled.  Same happens for live tv.  The normal ivtv test, cat
/dev/video0 > test.mpg, works fine with low cpu (around 8%) and nothing in
dmesg even when run for more than an hour.  I keep thinking it's an ivtv
problem for some reason...  but this would seem to imply that it isn't.

Any suggestions?  I'm at a dead end...

The machine is a P4 2.4GHz machine, intel mobo,  two SATA drives, one PVR-500.
It's running gentoo, with these versions of things I think mater:

sys-kernel/gentoo-sources-2.6.18-r6
media-tv/mythtv-0.20_p12376
media-tv/ivtv-0.8.2-r1
media-tv/pvr-firmware-20061007

Some things I've already tried:

Originally gentoo-sources-2.6.16 and ivtv-0.6.5.  Upgraded to ivtv-0.6.6, and
finally to what's listed above (gentoo-sources-2.6.18-r6 and ivtv-0.8.2-r1).

I also tried media-tv/mythtv-0.20_p12172 and media-tv/mythtv-0.20_p12325.  

Made sure it's using 720x480 resolution, to avoid VBI issue with saa7115.  

Kernel is not SMP.

Removed all old copies of the firmware and kernel modules, and then rebuilt
the kernel and ivtv.  


Here's the message from ivtv, repeated about once a second.  

ivtv0: All encoder MPEG stream buffers are full.  Dropping data.
ivtv0: Cause: the application is not reading fast enough.

Here's the info from loading ivtv.  

Jan  9 23:35:26 electron ivtv:  ==================== START INIT IVTV ====================
Jan  9 23:35:26 electron ivtv:  version 0.8.2 (tagged release) loading
Jan  9 23:35:26 electron ivtv:  Linux version: 2.6.18-gentoo-r6 preempt mod_unload PENTIUM4 gcc-3.4
Jan  9 23:35:26 electron ivtv:  In case of problems please include the debug info between
Jan  9 23:35:26 electron ivtv:  the START INIT IVTV and END INIT IVTV lines, along with
Jan  9 23:35:26 electron ivtv:  any module options, when mailing the ivtv-users mailinglist.
Jan  9 23:35:26 electron ivtv0: Autodetected Hauppauge card (cx23416 based)
Jan  9 23:35:26 electron ACPI: PCI Interrupt 0000:03:08.0[A] -> Link [LNKC] -> GSI 10 (level, low) -> IRQ 10
Jan  9 23:35:26 electron ivtv0: Unreasonably low latency timer, setting to 64 (was 32)
Jan  9 23:35:26 electron ACPI: PCI Interrupt 0000:01:00.0[A] -> Link [LNKA] -> GSI 11 (level, low) -> IRQ 11
Jan  9 23:35:26 electron ivtv0: loaded v4l-cx2341x-enc.fw firmware (262144 bytes)
Jan  9 23:35:26 electron tveeprom 1-0050: Hauppauge model 23552, rev D592, serial# 8221557
Jan  9 23:35:26 electron tveeprom 1-0050: tuner model is Philips FQ1236A MK4 (idx 92, type 57)
Jan  9 23:35:26 electron tveeprom 1-0050: TV standards NTSC(M) (eeprom 0x08)
Jan  9 23:35:26 electron tveeprom 1-0050: second tuner model is Philips TEA5768HL FM Radio (idx 101, type 62)
Jan  9 23:35:26 electron tveeprom 1-0050: audio processor is CX25843 (idx 37)
Jan  9 23:35:26 electron tveeprom 1-0050: decoder processor is CX25843 (idx 30)
Jan  9 23:35:26 electron tveeprom 1-0050: has radio, has no IR remote
Jan  9 23:35:26 electron ivtv0: Autodetected WinTV PVR 500 (unit #1)
Jan  9 23:35:26 electron tuner 1-0043: chip found @ 0x86 (ivtv i2c driver #0)
Jan  9 23:35:26 electron tda9887 1-0043: tda988[5/6/7] found @ 0x43 (tuner)
Jan  9 23:35:26 electron tuner 1-0060: TEA5767 detected.
Jan  9 23:35:26 electron tuner 1-0060: chip found @ 0xc0 (ivtv i2c driver #0)
Jan  9 23:35:26 electron tuner 1-0060: type set to 62 (Philips TEA5767HN FM Radio)
Jan  9 23:35:26 electron tuner 1-0061: chip found @ 0xc2 (ivtv i2c driver #0)
Jan  9 23:35:26 electron cx25840 1-0044: cx25843-23 found @ 0x88 (ivtv i2c driver #0)
Jan  9 23:35:26 electron cx25840 1-0044: loaded v4l-cx25840.fw firmware (16382 bytes)
Jan  9 23:35:26 electron wm8775 1-001b: chip found @ 0x36 (ivtv i2c driver #0)
Jan  9 23:35:26 electron ivtv0: Encoder revision: 0x02050032
Jan  9 23:35:26 electron ivtv0: Registered device video0 for encoder MPEG
Jan  9 23:35:26 electron ivtv0: Registered device video32 for encoder YUV
Jan  9 23:35:26 electron ivtv0: Registered device vbi0 for encoder VBI
Jan  9 23:35:26 electron ivtv0: Registered device video24 for encoder PCM audio
Jan  9 23:35:26 electron ivtv0: Registered device radio0 for encoder radio
Jan  9 23:35:26 electron tuner 1-0061: type set to 57 (Philips FQ1236A MK4)
Jan  9 23:35:26 electron ivtv0: Initialized WinTV PVR 500 (unit #1), card #0
Jan  9 23:35:26 electron ivtv:  ======================  NEXT CARD  ======================
Jan  9 23:35:26 electron ivtv1: Autodetected Hauppauge card (cx23416 based)
Jan  9 23:35:26 electron ACPI: PCI Interrupt 0000:03:09.0[A] -> Link [LNKH] -> GSI 9 (level, low) -> IRQ 9
Jan  9 23:35:26 electron ivtv1: Unreasonably low latency timer, setting to 64 (was 32)
Jan  9 23:35:26 electron ivtv1: loaded v4l-cx2341x-enc.fw firmware (262144 bytes)
Jan  9 23:35:26 electron tuner 2-0043: chip found @ 0x86 (ivtv i2c driver #1)
Jan  9 23:35:26 electron tda9887 2-0043: tda988[5/6/7] found @ 0x43 (tuner)
Jan  9 23:35:26 electron tuner 2-0061: chip found @ 0xc2 (ivtv i2c driver #1)
Jan  9 23:35:26 electron cx25840 2-0044: cx25843-23 found @ 0x88 (ivtv i2c driver #1)
Jan  9 23:35:26 electron cx25840 2-0044: loaded v4l-cx25840.fw firmware (16382 bytes)
Jan  9 23:35:26 electron wm8775 2-001b: chip found @ 0x36 (ivtv i2c driver #1)
Jan  9 23:35:26 electron tveeprom 2-0050: Hauppauge model 23552, rev D592, serial# 8221557
Jan  9 23:35:26 electron tveeprom 2-0050: tuner model is Philips FQ1236A MK4 (idx 92, type 57)
Jan  9 23:35:26 electron tveeprom 2-0050: TV standards NTSC(M) (eeprom 0x08)
Jan  9 23:35:26 electron tveeprom 2-0050: second tuner model is Philips TEA5768HL FM Radio (idx 101, type 62)
Jan  9 23:35:26 electron tveeprom 2-0050: audio processor is CX25843 (idx 37)
Jan  9 23:35:26 electron tveeprom 2-0050: decoder processor is CX25843 (idx 30)
Jan  9 23:35:26 electron tveeprom 2-0050: has radio, has no IR remote
Jan  9 23:35:26 electron ivtv1: Correcting tveeprom data: no radio present on second unit
Jan  9 23:35:26 electron ivtv1: Autodetected WinTV PVR 500 (unit #2)
Jan  9 23:35:26 electron ivtv1: Encoder revision: 0x02050032
Jan  9 23:35:26 electron ivtv1: Registered device video1 for encoder MPEG
Jan  9 23:35:26 electron ivtv1: Registered device video33 for encoder YUV
Jan  9 23:35:26 electron ivtv1: Registered device vbi1 for encoder VBI
Jan  9 23:35:26 electron ivtv1: Registered device video25 for encoder PCM audio
Jan  9 23:35:26 electron tuner 2-0061: type set to 57 (Philips FQ1236A MK4)
Jan  9 23:35:26 electron ivtv1: Initialized WinTV PVR 500 (unit #2), card #1
Jan  9 23:35:26 electron NVRM: loading NVIDIA Linux x86 Kernel Module  1.0-9631  Thu Nov  9 17:38:10 PST 2006
Jan  9 23:35:26 electron ivtv:  ====================  END INIT IVTV  ====================