Messages in this thread | | | Date | Tue, 5 Sep 2017 19:58:38 +0900 | From | Byungchul Park <> | Subject | Re: [PATCH 4/4] lockdep: Fix workqueue crossrelease annotation |
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On Tue, Sep 05, 2017 at 07:31:44PM +0900, Byungchul Park wrote: > Recursive-read and the hint I proposed(a.k.a. might) should be used for > their different specific applications. Both meaning and constraints of > them are totally different. > > Using a right function semantically is more important than making it > just work, as you know. Wrong?
For example, _semantically_:
lock(A) -> recursive-read(A), end in a deadlock, while lock(A) -> might(A) , is like nothing.
recursive-read(A) -> might(A), is like nothing, while might(A) -> recursive-read(A), end in a deadlock.
And so on...
Of course, in the following cases, the results are same:
recursive-read(A) -> recursive-read(A), is like nothing, and also might(A) -> might(A) , is like nothing.
recursive-read(A) -> lock(A), end in a deadlock, and also might(A) -> lock(A), end in a deadlock.
Futhermore, recursive-read-might() can be used if needed, since their semantics are orthogonal so they can be used in mixed forms.
I really hope you accept the new semantics... I think current workqueue code exactly needs the semantics.
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