Re: 100% system CPU usage with cdrecord

[Andreas Metzler <ametzler@logic.univie.ac.at>]

Charles Steinkuehler <charles@steinkuehler.net> wrote:
[...]
> Just so I'm clear, for best results...
> 
> If using a 2.6 kernel, I should use the ATAPI interface, ie:
>   cdrecord dev=ATAPI:0,0,0 ...
>     with no special kernel options at boot

No.

Quoting README.ATAPI:
-       Linux-2.4.xx includes a CDROM Packet interface in the
        IDE CD driver. For this driver libscg now includes
        support in pre-alpha status. Use cdrecord dev=ATAPI
-       Starting with Linux-2.5.45, there is a new experimental
        ATAPI interface [...] Cdrecord allows to use this interface 
        by calling e.g. cdrecord dev=ATA:1,0,0 
[...]

You want dev=ATA:x,y.z.

> ...but if I'm using a 2.4 kernel, even though the ATAPI interface is 
> there (and seems to be working), I should use SCSI emulation, ie:
>   cdrecord dev=0,0,0 ...
>     with hdX=ide-scsi in kernel command line at boot

Correct. Because quoting README.ATAPI again:
       All Linux ATAPI transport implementations do not support DMA.
        Current execptions are:

        -       ide-scsi with block size 2048 and if DMA has been enabled

        -       The new experimental ....

No DMA = 100% CPU.
            cu andreas