On Mon, 2008-07-21 at 09:51 +0800, Zhao Yakui wrote: > On Sat, 2008-07-19 at 11:16 -0700, Daniel Walker wrote: > > Instead of re-using semaphores for the mutex operation, I've > > added usage of the kernel mutex for the os mutex implementation. > > > What is the advantage that the kernel mutex is used for the ACPI mutex > implementation instead of using semaphore? > And it seems that too much ACPICA source code is touched. In general you would want to use a mutex whenever your using mutex-like semantics. If I see a mutex used in code then I have a pretty good idea the locking is sane.. As Peter mentioned , you also get lockdep which helps to find lots of different locking problems. You can also look at Documentation/mutex-design.txt which has a fairly big list of benefits over the semaphore. (tho when that was written the semaphore implementation was different.) Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
