Date: Fri, 23 Apr 2004 13:49:13 -0400 From: John Baldwin <jhb@FreeBSD.org> To: "Artem Koutchine" <matrix@itlegion.ru> Cc: freebsd-hardware@FreeBSD.org Subject: Re: ACPI floods CPUs with interrupts Message-ID: <200404231349.13468.jhb@FreeBSD.org> In-Reply-To: <009f01c42870$deadb230$0c00a8c0@artem> References: <010501c426db$cc281a10$0c00a8c0@artem> <200404220913.02440.jhb@FreeBSD.org> <009f01c42870$deadb230$0c00a8c0@artem>
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On Thursday 22 April 2004 09:51 am, Artem Koutchine wrote: > > On Tuesday 20 April 2004 09:31 am, Artem Koutchine wrote: > > > I have installed FreeBSd 5.2-RC2 on ASUS P2B-DS > > > with 3ware raid controller and DUAL PIII (slot2) 550Mhz. > > > Updated motherboard bios to > > > the latest bios and after patching the twe driver, so it does not > > > show the "PCI parity erro" several times a second. (I think > > > it is related to the fact that 3ware 7506 controller is pci 2.2 > > > while p2b is pci 2.1). After that i did top and saw that > > > 50% of cpu power is wasted on interrupts. I did > > > sysstat and :vmstat. It showed that 46700 interrupts per > > > second were generated by acpi on irq 20. So, i booted without > > > acpi and got 100% cpu idle. The question is: > > > How ACPI can generate IRQs? I thought it is just some kind > > > of interface and protocol standard, not > a real hardware part which > > > can rise irq. Why does it generate so many irqs? May it be related > > > to the PCI parity error on twe? > > > > It is because the ACPI interrupt is programmed incorrectly (due to a > > buggy BIOS) and is treated as edge triggered when it is actually level > > triggered. You can try updating to -current to see if that fixes it. > > Cvsupped -current today and built world and installed new kernel. Now it > actually detects the interrupt storm and does what it calles 'thottling' to > the source of the interrupts. Now i get only 9000 ints per second and it > eats abouts 10% of the CPU. I still do not consider it a good idea and i > cannot update bios because the latest update was in 2002 and since then > asus made no changed to it. So i just did hint.acpi.0.disabled="1" and > disabled acpi. Now i have all 100% of cpu to do something usefull. ACPI is > a good thing but it is totally broken on all motherboards. Too bad. ACPI is not totally broken on all motherboards. Can you try adding 'hw.acpi.force_sci_lo=1' to /boot/loader.conf and rebooting to see if it works better? -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org
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