Re: Slow Disk I/O with QPS M3 80GB HD

From: H . J . Lu (hjl@lucon.org)
Date: Tue Dec 11 2001 - 11:45:52 EST


On Tue, Dec 11, 2001 at 11:05:07AM -0500, Ben Collins wrote:
> On Mon, Dec 10, 2001 at 11:57:08PM -0800, H . J . Lu wrote:
> > On Mon, Dec 10, 2001 at 08:34:52PM -0800, H . J . Lu wrote:
> > > I have a very strange problem. The disk I/O of my QPS M3 80GB HD is
> > > very slow under 2.4.10 and above. I got like 1.77 MB/s from hdparm.
> > > But under 2.4.9, I got 14 MB/s on the same hardware. A 30GB HD has
> > > consistent I/O performance under 2.4.9 and above on the same bus. Has
> > > anyone else seen this? Does anyone have a large (>= 80GB) 1394 HD?
> > >
> >
> > I did a binary search. 2.4.10-pre10 is the last good kernel. I got
> >
> > # hdparm -t /dev/sda
> >
> > /dev/sda:
> > Timing buffered disk reads: 64 MB in 4.40 seconds = 14.55 MB/sec
>
> Have you checked the way that your ohci and sbp2 devices are detected
> under each case? Most notably the max packet size.
>

They all say

ohci1394_0: OHCI-1394 1.0 (PCI): IRQ=[19] MMIO=[f8ffd000-f8ffe000] Max Packet=[1024]
ieee1394: sbp2: SBP-2 device max speed S200 and payload 1KB

H.J.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sat Dec 15 2001 - 21:00:20 EST