Re: hdparm and DMA
On Mon, Nov 18, 2002 at 14:46:27 +0100, Emil Pedersen wrote:
>
> [...]
>
> > Now the kernel I am using I compiled myself and I selected to use DMA
> > when available. Here is part of the kernel config:
> > CONFIG_BLK_DEV_IDEPCI=y
> > CONFIG_IDEPCI_SHARE_IRQ=y
> > CONFIG_BLK_DEV_IDEDMA_PCI=y
> > CONFIG_BLK_DEV_ADMA=y
> > # CONFIG_BLK_DEV_OFFBOARD is not set
> > CONFIG_IDEDMA_PCI_AUTO=y
> > CONFIG_BLK_DEV_IDEDMA=y
> >
> > Now when I check with hdparm I get:
> > # hdparm /dev/hda
> >
> > /dev/hda:
> > multcount = 0 (off)
> > I/O support = 0 (default 16-bit)
> > unmaskirq = 0 (off)
> > using_dma = 0 (off)
> > keepsettings = 0 (off)
> > nowerr = 0 (off)
> > readonly = 0 (off)
> > readahead = 8 (on)
> > geometry = 77545/16/63, sectors = 78165360, start = 0
> > busstate = 1 (on)
> >
> > So it seems it is not on?
>
> I've noticed the same behavior with one of my extra ide-cards, a Promise
> Ultra100 TX2 (does 'pdc20268' as chipset make sense, can't remeber).
> The other card (a hpt366 based IWill <something>) as well as the
> onboard (intel something i think) works fine though, so the behavior
> seems to be chip dependent.
>
>
> [...]
>
> > But rechecking to see if changes have worked:
> > hdparm /dev/hda
> > give exactly the same output as above. Rechecking the speeds and these
> > are the same too.
> >
> > I guess it is turned on already and the drives won't tell hdparm, or it
> > can't be turned on anyway.
>
> Hmm, if you try to turn it OFF, does the output from 'hdparm /dev/hda'
> change?
>
> I really have no idea what to do when hdparm fails, sorry.
>
It makes no difference:
# hdparm -c0 -d0 /dev/hda
/dev/hda:
setting 32-bit I/O support flag to 0
setting using_dma to 0 (off)
I/O support = 0 (default 16-bit)
using_dma = 0 (off)
# hdparm /dev/hda
/dev/hda:
multcount = 0 (off)
I/O support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 0 (off)
keepsettings = 0 (off)
nowerr = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 77545/16/63, sectors = 78165360, start = 0
busstate = 1 (on)
# hdparm -tT /dev/hda
/dev/hda:
Timing buffer-cache reads: 128 MB in 0.46 seconds =278.26 MB/sec
Timing buffered disk reads: 64 MB in 16.12 seconds = 3.97 MB/sec
Thus all the same as before whether turned on or off. I also tried
setting MultiSect to max of 16 (which hdparm -i told me it could do),
but this didn't change things either.
So are the read times as expected for an IDE ATA133, 7200RPM, 40GB drive?
This is one of the faster IDE drives now isn't it?
Cheers.
Mark.
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