[mythtv-users] Sound jerkiness with latest RedHat kernel

[Flavio Villanustre]

Hi all,

I'm currently using kernel 2.4.20-18.9 from RedHat. Since the latest 
kernel upgrade I started noticing choppy audio and playback slowly lagging 
behind live TV (after about 20 minutes of live TV, it's about 2 minutes 
behind).

I'm using a PVR250 with a Pentium IV 2.4Ghz. CPU usage is really low 
(below 6% user time and below 4% user time). I'm using an ultra ATA ide 
subsystem with a dedicated disk for the ringbuffer/store.

I've have DMA enabled and a few tweaks on the HD:
/sbin/hdparm -X70 -c1 -W1 -A1 -a128 -u1 /dev/hdb

I tuned the elevator:
/sbin/elvtune -r 2048 -w 4096 -b 0 /dev/hdb

And I reduced the bitrate of the PVR:
/usr/local/bin/test_ioctl -d /dev/video0 -c bitrate=2500000,bitrate_peak=8000000

iostat results are:
avg-cpu:  %user   %nice    %sys   %idle
           5.00    0.00    4.00   91.00

Device:    rrqm/s wrqm/s   r/s   w/s  rsec/s  wsec/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await  svctm  %util
/dev/hdb     0.00 142.00  0.00 36.00    0.00 1424.00     0.00   712.00    39.56 42949613.96    2.78  27.78 100.00


However I had little success.

I've seen several messages posted to this mailing list complaining about
RedHat kernels. Could anybody solve this? Is anybody using latest RedHat
kernel without problems?

Thanks and best regards,

Flavio