Messages in this thread | | | Date | Mon, 30 Nov 2009 08:57:46 +0100 | From | Nick Piggin <> | Subject | Re: [rfc] "fair" rw spinlocks |
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On Sun, Nov 29, 2009 at 10:51:22AM -0800, Paul E. McKenney wrote: > On Sat, Nov 28, 2009 at 09:30:18AM -0800, Linus Torvalds wrote: > > So as far as I can tell, we have only one real user of rwlocks where > > livelocks might be relevant, but that one real user absolutely _requires_ > > the unfair behavior. > > But the required unfairness is limited to unconditionally granting > recursive read requests, right? If I understand correctly, if a given > CPU does not already read-hold the lock, then we can safely make that > CPU wait for a writer that might otherwise be starved. Again, is there > another requirement that I am missing?
I think this is the only ordering requirement.
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