Re: [PATCH 6/6] x86 rwsem: more precise rwsem_is_contended()implementation

[Peter Zijlstra]

On Thu, 2010-12-02 at 16:16 -0800, Michel Lespinasse wrote:
> We would like rwsem_is_contended() to return true only once a contending
> writer has had a chance to insert itself onto the rwsem wait queue.
> To that end, we need to differenciate between active and queued writers.

So you're only considering writer-writer contention? Not writer-reader
and reader-writer contention?

I'd argue rwsem_is_contended() should return true if there is _any_
blocked task, be it a read or a writer.

If you want something else call it something else, like
rwsem_is_write_contended() (there's a pending writer), or
rwsem_is_read_contended() (there's a pending reader).


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