Re: PATCH: cdrecord: avoiding scsi device numbering for ide devices

Albert Cahalan
2004-08-10T03:33:07Z

On Mon, 2004-08-09 at 18:59, Con Kolivas wrote:
> Albert Cahalan writes:
>
>
> > Joerg:
> > "WARNING: Cannot do mlockall(2).\n"
> > "WARNING: This causes a high risk for buffer underruns.\n"
> > Fixed:
> > "Warning: You don't have permission to lock memory.\n"
> > " If the computer is not idle, the CD may be ruined.\n"
> >
> > Joerg:
> > "WARNING: Cannot set priority class parameters priocntl(PC_SETPARMS)\n"
> > "WARNING: This causes a high risk for buffer underruns.\n"
> > Fixed:
> > "Warning: You don't have permission to hog the CPU.\n"
> > " If the computer is not idle, the CD may be ruined.\n"
>
> Huh? That can't be right. Every cd burner this side of the 21st century has
> buffer underrun protection.

I'm pretty sure my FireWire CD-RW/CD-R is from
another century. Not that it's unusual in 2004.

> I've burnt cds _while_ capturing and encoding
> video using truckloads of cpu and I/O without superuser privileges, had all
> the cdrecord warnings and didn't have a buffer underrun.

That's cool. My hardware won't come close to that.
Burning a coaster costs money.

Let me put it this way: $$ $ $$$ $$ $ $$$ $$ $

The warning, if re-worded, will save people from
frustration and wasted money.

> Last time I gave
> superuser privilege to cdrecord it locked my machine - clearly it wasn't
> rt_task safe.

So, you've been working on the scheduler anyway...
An option to reserve some portion of CPU time for
emergency use (say, 5% after 1 second has passed)
would let somebody get out of this situation.

Reporting and/or fixing the cdrecord bug is nice too.