RE: [PATCH 1/3] acpi: add real mutex function calls

Daniel Walker
2008-07-24T12:45:03Z

(Added back the CC list.)

I don't think the problem is in the machine specific ACPI info .. As far
as I can tell the problem is related to how the interpreter lock is
interleaved with the AML mutexes . For example, a series of AML locks
can be A->B->C and at any point the interpreter lock can be released,
and reacquired. So you have a possible lock sequence of I->A->B->C ,
then in another path you have A->I->B->C. That creates a circular lock
scenario and with multiple threads in those different paths you could
end up with a deadlock (or a lockdep warning).

I was also reading the ACPI spec on how the ASL compiler does checking
on mutex usage similar to what lockdep is doing. I would hope there are
no lockdep warning coming from that code.

Daniel