Messages in this thread | | | Date | Tue, 21 Jan 2014 16:41:13 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v8 4/4] qrwlock: Use smp_store_release() in write_unlock() |
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On Tue, Jan 21, 2014 at 10:02:06AM -0500, Waiman Long wrote: > My latest v9 series of qrwlock patch will automatically adapt to the lack of > atomic byte access by using an atomic integer instruction instead. So the > new series should work for pre-EV56 Alpha, it is just a bit less efficient > in this case.
See my other email; I don't think you can do that without also changing the implementation of the queue_read_{try}lock() functions.
Without those changes you can have transient values in your 'read-count' part of the word and a full word write will wreck things.
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