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Re: FIXED: mpt Serious performance issues

On Wed, 9 Feb 2011, Michael L. Hitch wrote:

That would be because both FreeBSD and OpenBSD have totally rewritten their driver. It did not appear that either driver clears the SCSI DEVICE page.

Started looking through the FreeBSD driver, and they do reset the SCSI DEVICE pages - but only if the BIOS has not negotiated target speeds. Since the BIOS will usually have done all that during the controller initialization, the FreeBSD driver would normally not touch those pages. Although I do see where it will update the page individually, but I'm not sure what conditions that would occur on. I would hope that it's only if the driver is using the physical drives directly. [It looks like it's likely done in the CAM layer somewhere.]

Michael L. Hitch              
Computer Consultant
Information Technology Center
Montana State University        Bozeman, MT     USA

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