Date: Wed, 10 Sep 1997 14:59:38 +0200 From: Mats Lofkvist <mal@algonet.se> To: se@freebsd.org Cc: current@freebsd.org Subject: Re: lousy disk perf. under cpu load (was IDE vs SCSI) Message-ID: <199709101259.OAA02564@kairos> In-Reply-To: <19970909231006.58788@mi.uni-koeln.de> (message from Stefan Esser on Tue, 9 Sep 1997 23:10:06 %2B0200)
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Hmmm, you got all your PCI disk and LAN cards on
IRQ 10, which means there are three cards sharing
interrupts. The VGA is on IRQ 11, and it should
not really cause interrupts ...
Could you try to assign different IRQs to fxp0, ncr0
and ahc0 ?
Shared interrupts should just work, and there should
not be a measurable impact on performance, but this
is the only thing that seems special in your system.
Regards, STefan
Reassigning interrupts doesn't seem to be as easy as I hoped :-(
I have an Intel Providence motherboard with the ahc and fxp
builtin (on pci) and an separate ncr for the narrow devices.
I haven't been able to figure out how to change the interrupts,
can't find anything in the bios letting me set them explicitly.
(Setting plug-n-play to "bios" mode only lets me reserve irq's
used by non-pnp cards, not reassign anything on pci. With pnp in
the "pnp os" mode nothing can be changed.)
Any ideas?
_
Mats Lofkvist
mal@algonet.se
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