HI all!

I got a gentoo linux. I installed it ok.
The biggest ( and the stranger one ) problem is that I met is that when I perform some job
( like file copying, compiling , cd burning ) the whole my system is almost stuck , and I couldn't do anything on it.
I tried to use > top -> press r -> renice a process that slow down my system ( tip that I get from this site ) ; but 1. I seems to work inefficiently
2. What could I do if process PID changes (like in "emerge something" ) ?

This was't a problem when I used other distro ( actually other kernel )
Its is really frustrating because even I delete a lot of files from mc ( > 1GB ) , in other xterm I barely can type something.

I suppose I compiled kernel not very appropriately.
Is there I kernel compilation option so that to schedule system to perform background process with less priority ?

Any suggestion are welcome.

Do you have dma enabled on your hard disk. Check with "hdparm /dev/hda" (hda is your first hard disk, hdb your second). If not you can try setting it with "hdparm -d1 /dev/hda" but chances are you missed it in your kernel configuration so you have to enable it there. I think it was under IDE, ATA and ATAPI drivers.

here is my :

when I
And , yes , in my /usr/src/linux/.config for current kernel I got

make menuconfig -> Device Drivers -> ATA/ATAPI/ MFM/ RLL support -> Enable DMA for disks only DISABLED

Is this right check for "enabling DMA " ?

Nope you need it on enabled (you need to compile it in, not as module) in the kernel. So you have to recompile it. Then you do the command "hdparm -d1 /dev/hda" it should work then and it should be a lot better

I enabled option

Device Drivers -> ATA/ATAPI/ MFM/ RLL support -> Enable DMA for disks only

from make menuconfig menu ( built in , not as a module ),and recompiled the kernel.

I works !!!
Finally !!!
Even without
> hdparm -d1
(
because when I type hdparm initally it shows :
/dev/hda:
multcount = 16 (on)
IO_support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 0 (off)
readonly = 0 (off)
readahead = 256 (on)
geometry = 65535/16/63, sectors = 41110142976, start = 0

i.e. using_dma = 1 (on)

)


thank you,darkleaf, you've really helped me.

It works !!! -- means that my systems runs OK even when I do lenghty jobs , like cd burning ...

No problem Glad it got fixed. I have had dma off for a year or so before I asked on here so I know hoe bad it is