Binary package hint: acpi
On my Vaio SR17 laptop, when I run a CPU-intensive process (like compiling a large program), eventually kacpi_notify always begins to take 85% or more of the machine's CPU. I can't kill kacpi, even with -9, and I can't even shut down gracefully: the machine gets through most of the shutdown sequence and then sits there with the CPU still spinning, and I have to pull the power plug.
This machine worked fine under Breezy. Please, is there any way I can disable kacpid, or control its function? I don't think it's doing anything I need (CPU speeds and the CPU fan are controlled in BIOS on this machine). Google finds tons of people having similar problems, but nobody seems to know a fix. I don't want to disable acpi entirely since ubuntu's excellent acpi suspend/hibernate support (in breezy, anyway) is the biggest reason I prefer ubuntu on this laptop.
Answering my own plea: it looks like killing acpid before starting anything CPU intensive prevents the runaway kacpi_notify process. At least, I made it through a complete gimp build, which is a lot farther than I ever got when acpid was running.
I'd welcome suggestions as to how to pin this down more specifically -- perhaps there's some configuration option I could change to avoid the runaway. I'm not sure where to start in /etc/acpi.
I did find some speculation (but no confirmation) that the problem has something to do with monitoring temperature. Maybe if the temp goes too high, that freaks kacpi out for some reason, ironically sending it into a CPU-spinning feedback loop that ensures the temperature stays high?