Re: scheduling while atomic acpi_idle_enter_bm

From: Len Brown
Date: Mon Nov 02 2009 - 22:04:05 EST

> > I get this when modprobing some module I am working on. I figured it
> > was the module's fault but the EIP points to something else so I am
> > not sure. I get the following repeating about 4 times on 2.6.32-rc5:
> you can get this if your own code leaves interrupts disabled in a
> kernel thread and then lets the cpu go idle...


acpi_enter_idle_bm() assumes that it is entered with irqs enabled,
and so it we unconditionally disables IRQs.

Then we unconditionally re-enable them.

The problem seems to be that right after we enable them,
we find that they are actually disabled, perhaps as
a side-effect of SMM.

Is your machine a Dell, per chance?

Please test the patches in this bug report:

Len Brown, Intel Open Source Technology Center
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