On Wed, 4 Sep 2002 10:55:37 -0400, Benjamin LaHaise <bcrl@redhat.com> wrote:
> Have you tried commenting out the hdparm commands in the initscripts and
> booted with a kernel that enables DMA (instead of using hdparm -d1)?
>
> -ben
I can give that a whirl, but it bothers me the way it currently
"works":
* Performance is terrible
* booting with noapic makes no difference
* Performance seems to indicate some kind of difficulties in
the kernel, perhaps connected to interrupt handling
I have another RH 7.3 box sitting next to the new one, which has
a Sony DVD-ROM. I just enabled DMA with hdparm and it works very
well. That is not what happens on the other (troublesome) machine.
So I am wondering:
* Kernel interrupt handling problem (should there be ERR if
apic is enabled? which it is)
* IRQ problem? I haven't tried changing around IRQs.
* IDE controller problem? Probably not, because the drive seems
to work the same on the Highpoint controller.
* Problem with this specific drive? Perhaps. I've never used it
before--the last "combo" drive I used was SCSI. I bought this
one because it was the same brand as the SCSI drive I used before,
and as an IDE device it would be about $500 cheaper (no SCSI
card needed). I will check to see if a firmware download is
available.
* Some other m/b problem? Perhaps, but I've not tried this drive
in another box. I am inclined to try that next.
I am also inclined to try the Sony DVD-ROM in the new box to see
if it exhibits the same behavior.
What is the "combo drive" used by the iMac et al.?
-joseph
>
> On Tue, Sep 03, 2002 at 11:00:00PM -0700, Joseph N. Hall wrote:
> > Yes, DMA makes the drive completely non functional and eventually
> > hangs the machine after some amount of attempted use. This is
> > regardless of when DMA is enabled, whether via the standard
> > RedHat "harddiskn" mechanism or manually with hdparm.
> >
> > -joseph
> >
> > On Tue, 3 Sep 2002 22:37:57 -0700, Matthew Dharm <mdharm-kernel@one-eyed-alien.net> wrote:
> > >
> > > Have you tried enabling DMA on the drive?
> > >
> > > Matt
> > >
> > > On Tue, Sep 03, 2002 at 06:45:00PM -0700, Joseph N. Hall wrote:
> > > > Dear Kernel Folks,
> > > >
> > > > I am trying to determine the cause of the poor performance of a
> > > > an IDE DVD device on my new machine. I have an IDE Panasonic DF-210-type
> > > > DVD-RAM/R/ROM in a new machine with Soyo KT333 motherboard. It
> > > > transfers data slowly (below DVD speed), consumes large amounts of
> > > > system time, and slows down the user interface and even system
> > > > clock (which can run as slow as 1/4 speed while the drive is
> > > > going).
> > > >
> > > > The interrupt ERR count below seems to be mostly related to use
> > > > of the DVD drive.
> > > >
> > > > Maybe it's something simple. If not, I'll be glad to do further
> > > > work to help diagnose the problem.
>
> --
> "You will be reincarnated as a toad; and you will be much happier."
>
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