Re: Async resume patch (was: Re: [GIT PULL] PM updates for 2.6.33)

From: Linus Torvalds
Date: Tue Dec 08 2009 - 10:36:03 EST




On Tue, 8 Dec 2009, Rafael J. Wysocki wrote:
>
> The wait queue plus the op_complete flag combo plays the role of the locking
> in the Linus' picture

Please just use the lock. Don't make up your own locking crap. Really.

Your patch is horrible. Exactly because your locking is horribly
mis-designed. You can't say things are complete from an interrupt, for
example, since you made it some random bitfield, which has unknown
characteristics (ie non-atomic read-modify-write etc).

The fact is, any time anybody makes up a new locking mechanism, THEY
ALWAYS GET IT WRONG. Don't do it.

I suggested using the rwsem locking for a good reason. It made sense. It
was simpler. Just do it that way, stop making up crap.

Linus
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