Date: Wed, 10 Sep 1997 15:42:51 +0200 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: Mats Lofkvist <mal@algonet.se> Cc: se@freebsd.org, current@freebsd.org Subject: Re: lousy disk perf. under cpu load (was IDE vs SCSI) Message-ID: <1237.873898971@critter.freebsd.dk> In-Reply-To: Your message of "Wed, 10 Sep 1997 14:59:38 %2B0200." <199709101259.OAA02564@kairos>
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In message <199709101259.OAA02564@kairos>, Mats Lofkvist writes: > 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? This card is rather stubborn, (I've got one too), Try setting the setting to "APIC" somewhere deep in there, that may help. Quite possibly this will make no difference unless you boot a SMP kernel, but that will probably work OK even if you only have one CPU. -- Poul-Henning Kamp FreeBSD coreteam member phk@FreeBSD.ORG "Real hackers run -current on their laptop."
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