Date: Tue, 9 Sep 1997 23:10:06 +0200 From: Stefan Esser <se@FreeBSD.ORG> To: Mats Lofkvist <mal@algonet.se> Cc: current@FreeBSD.ORG Subject: Re: lousy disk perf. under cpu load (was IDE vs SCSI) Message-ID: <19970909231006.58788@mi.uni-koeln.de> In-Reply-To: <199709082256.AAA04008@kairos>; from Mats Lofkvist on Tue, Sep 09, 1997 at 12:56:05AM %2B0200 References: <199709082256.AAA04008@kairos>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sep 9, Mats Lofkvist <mal@algonet.se> wrote: > I tested reading (and writing were possible) small blocks (4KB) on all > my devices tonight. With iozone and bonnie I don't see anything really > alarming except that the bonnie seek rate drops significantly when > a "loader" is running (*). But dd from (and to) all my devices show the same > results counting the number of transfers per second (= # pci interrupts / s): > > rst0 r rst0 w sd0 rsd0 sd1 rsd1 cd0 rcd0 > unloaded 283 294 3700 2600 1134 1049 900 460 > loaded 23 22 50 26 24 23 25 22 > > rst0 is a sony sdt7000 dat tape on the ncr > sd0 is a quantum viking w on the aic7880 > sd1 is a quantum capella on the ncr > cd0 is a pioneer dr-u12x on the ncr I definitely can't reproduce your numbers. There is something *very* wrong with your system! > chip0 <Intel 82440FX (Natoma) PCI and memory controller> rev 2 on pci0:0 > fxp0 <Intel EtherExpress Pro 10/100B Ethernet> rev 1 int a irq 10 on pci0:6 > ahc0 <Adaptec aic7880 Ultra SCSI host adapter> rev 0 int a irq 10 on pci0:9 > vga0 <VGA-compatible display device> rev 0 int a irq 11 on pci0:11 > ncr0 <ncr 53c810a scsi> rev 18 int a irq 10 on pci0:17 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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?19970909231006.58788>