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I'm wondering if anyone has seen this before, and could perhaps shed some light on a solution.

I'm running Red Hat Enterprise Linux 6.1, fully updated in a text-only server configuration, and the kacpid and kacpi_notify processes have started to take up ~70% and ~15% of CPU time, respectively. I've traced the problem to what looks like an insane amount of ACPI interrupts:

[root@centauri ~]# cat /proc/interrupts | grep acpi; sleep 5; cat /proc/interrupts | grep acpi
  9:     447753          0   32693472          0   IO-APIC-fasteoi   acpi
  9:     447753          0   32850749          0   IO-APIC-fasteoi   acpi

At over 30k interrupts a second, something is clearly wrong. Additionally, if I check another server with a very similar hardware configuration, the interrupt counts for this particular interrupt is always zero. Both systems are running Core i7 2600K processors with hyper-threading disabled. I've tried resetting all defaults in the BIOS, with no luck.

Any ideas what could cause such a high number of interrupts?

If I boot with acpi=off, this problem goes away. Besides power control, are there any drawbacks to running the system with ACPI disabled?

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migrated from Nov 14 '11 at 20:07

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Same firmware/BIOS version on both machines? – James Nov 15 '11 at 1:51
Not exactly. The two machines use different motherboard models (both Intel), so its not exactly the same BIOS. I did update the BIOS on the affected machine, with no change. – Justin Holewinski Nov 15 '11 at 17:51

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