[vdr] Re: Performanceproblem with vdr on Linux 2.4.4, reiserfs, raid5

[Emil Naepflein <Emil.Naepflein@philosys.de>]

On Tue, 18 Sep 2001 18:19:38 +0200, Marcus Kuba <marcus@kuba4u.de>
wrote:

Please set your line length to 72.

> Am 18.09.2001 13:39:44, schrieb Emil Naepflein <Emil.Naepflein@philosys.de>:
> 
> >could someone with a 2 or 3 DVB card system use vmstat and look how the
> >cpu usage is during 2 concurrent recordings and one playback, please?
> 
> I only have 2 cards.. so I can do only 2 recordings or 1 recording with playback/timeshift.
> 
> >I have noticed that the cpu usage goes up to 100 % on my 700 MHz Duron
> >system. The cpu time is used by bdflush. It would be interesting for me
> >to see how much cpu is used on other systems.
> 
> With a 500MHz Athlon, 256MB and a mixture of ext2fs and reiserfs I can hardly get a cpu usage higher than 10%. The only way to achieve this is a cutting-process or 
> using fast-for/backward replay because both require more harddisk-activity. bdflush is at 0.0%, and I have no raid5..

Maybe its an interaction with Raid5. I can remember that concurrently a
rebuild was running on another partition. but normally this runs at only
1 MB/s and the cpu time is much below 50 %. I will look into this
further.


> 
> >I also noticed that with VDR 0.84 and the driver downloaded from the vdr
> >homepage last sunday there are occassional dropouts in live viewing.
> 
> I have observed this once on Pro7 since installing the new VDR0.95 and the 09/16-driver, but it went away by switching channels back and forth.

With dropout I mean a very short interruption of the image (fraction of
a second). I have nothing to do to bring the image back. It is just like
when switching channels or starting and stopping playback. I shortly see
a blue background and then the image reappears. Mabe it is some stray
command which stops viewing shortly. The driver traces may help here.

Emil