processor priority?

fr0zen · 12-17-2003, 08:27 PM

I'm running LFS 5.0 with XFCE4.0.1.

I have a bit of a problem here that isn't a problem on Mandrake. Here's the problem: I've got XMMS open, and a shell open. Music is playing, and I'm (of course) working on something. I go to extract a compressed file, tar -xjf, it starts to decompress...and then, the music stutters. Then it stops completely. I have to 'killall xmms' in order to close xmms.

Compared to Mandrake, this simply does not occur. I can listen to music w/o such 'skipping' issues when the CPU is being utilized.

I don't think X has anything to do with it either, as I did a command line test (from 2 pty's). On one I started to uncompress linux 2.4.23.tar.bz2. I then switched over to the other and played a wav file. It played fine...for a few seconds. Then it stopped, and the following error was produced:

underrun! (at least 0.050 ms long)

I notice this isn't just for 'sound' either. Though, its more noticable with sound. When extracting, the GUI doesn't respond as quickly as it should. When extracting, keys aren't received as fast as normal (on another pty).

It's not just extracting; it's any CPU intensive operation. None of this seems to be a problem in MDK though. It seems like everything has the same priority level or something like that, so when another process is started it can consume as much of the CPU it wants thus affecting other processes.

Any ideas? Thanks.....please help.

Tinkster · 12-18-2003, 11:32 AM

hdparm /dev/hdX

I'd assume that DMA must be turned off
for the drive ....

Cheers,
Tink

fr0zen · 12-18-2003, 11:51 AM

Odd.

I don't seem to have this command available.

Tinkster · 12-18-2003, 12:00 PM

Did you su -
to become root? It's one of the potentially
dangerous commands that the normal user
isn't allowed ... if you actually don't have it,
get it ;0

Cheers,
Tink

fr0zen · 12-18-2003, 02:10 PM

Yes. I was logged in as root. I'll investigate getting this command.

fr0zen · 12-18-2003, 03:43 PM

I installed hdparm. I switched to single user mode (init 1) and attempted to modify the settings.

Seems everything was defaulted (though my hardware is very new), so I was far from using the optimal settings.

Only thing is, I tried to enable DMA...and I was given an error. "OPERATION NOT PERMITTED".

Apparently this is related to something I need to include into my kernel, not exactly sure what that is though. I do know that in MDK DMA is enabled, so my HD supports it.

Tinkster · 12-18-2003, 04:09 PM

less /usr/src/linux/.config
/DMA
v

:}

Cheers,
Tink

fr0zen · 12-19-2003, 11:54 AM

Just thought I'd post up saying that I got it working :P

Thanks for your help Tinkster, not quite sure how you knew the solution, but I'm glad someone did!

Code:

[root@FRoZiX ~]# /sbin/hdparm -tT /dev/hda

/dev/hda:
 Timing buffer-cache reads:   1352 MB in  2.00 seconds = 676.00 MB/sec
 Timing buffered disk reads:   92 MB in  3.06 seconds =  30.07 MB/sec
[root@FRoZiX ~]# /sbin/hdparm /dev/hda

/dev/hda:
 multcount    = 16 (on)
 IO_support   =  1 (32-bit)
 unmaskirq    =  1 (on)
 using_dma    =  1 (on)
 keepsettings =  0 (off)
 readonly     =  0 (off)
 readahead    =  8 (on)
 geometry     = 4982/255/63, sectors = 80043264, start = 0
[root@FRoZiX ~]#

Tinkster · 12-19-2003, 12:21 PM

Quote:

Originally posted by fr0zen
Just thought I'd post up saying that I got it working :P

Thanks for your help Tinkster, not quite sure how you knew the solution, but I'm glad someone did!

Glad you're all go, and I've just seen similar
posts quite often... that, combined with a passion
for puzzles and an inquisitive mind, and the
ability to use man and apropos ... LOL ...

Well, you get the idea: I like to solve other
peoples problems because it keeps me learning ;)

Cheers,
Tink

P.S.: If you feel I helped you, feel free to give
me an afero ;)