Messages in this thread | | | Date | Tue, 12 Jan 2016 10:06:29 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] rbtree: use READ_ONCE in RB_EMPTY_ROOT |
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On Mon, Jan 11, 2016 at 10:22:43AM -0800, Davidlohr Bueso wrote: > With d72da4a4d97 (rbtree: Make lockless searches non-fatal) our rbtrees > provide weak guarantees that allows us to do lockless (and very speculative) > reads of the tree. Such readers cannot see partial stores on nodes, ie > left/right as well as root. As such, similar to the WRITE_ONCE semantics when > doing rotations, use READ_ONCE when checking the root node in RB_EMPTY_ROOT.
No objection, but is this actually used anywhere?
Or is this a just-in-case completeness thing?
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