CONFIG_ACPI_PROCESSOR=y confuses the cpu scheduler

CONFIG_ACPI_PROCESSOR=y confuses the cpu scheduler

[Diego Calleja]

If I compile CONFIG_ACPI_PROCESSOR in the kernel, one of the two cpus
doesn't get scheduled any process. The CPU works and everything, it
services interrupts and I can force processes to run on that CPU
with taskset, but they won't get scheduled in that CPU no matter
how much processes and load you put on the machine.

However, when I compile it as a module everything works fine. I can't
say when this started happening; I noticed it in the current linus 
git tree from a couple of days ago, but testing 2.6.15-rc7 didn't
help. The machine is a dual P3 machine.

Here's a working dmesg: http://terra.es/personal/diegocg/dmesg-acpi
a dmesg of the machine after setting CONFIG_ACPI_PROCESSOR to y:
http://terra.es/personal/diegocg/dmesg-acpi-no
and a acpidump output: http://terra.es/personal/diegocg/acpidump

Re: CONFIG_ACPI_PROCESSOR=y confuses the cpu scheduler

[Diego Calleja]

El Thu, 19 Jan 2006 01:20:40 +0100,
Diego Calleja <diegocg@gmail.com> escribió:

> If I compile CONFIG_ACPI_PROCESSOR in the kernel, one of the two cpus
> doesn't get scheduled any process. The CPU works and everything, it
> services interrupts and I can force processes to run on that CPU
> with taskset, but they won't get scheduled in that CPU no matter
> how much processes and load you put on the machine.


This has been reported by another person who found the culprit
commit: http://bugzilla.kernel.org/show_bug.cgi?id=5930