review request (M): 7121140: Allocation paths require explicit memory synchronization operations for RMO systems
tom.rodriguez at oracle.com
Wed Dec 14 11:41:33 PST 2011
On Dec 14, 2011, at 7:55 AM, Roland Westrelin wrote:
> For systems that don't implement total store ordering a store store barrier is required after a newly allocated objects is initialized and before it becomes globally reachable.
I think the instruct name should be membar_storestoree instead of unnecessary_membar_storestore and remove the "unnecessary so" part of the comment. It's like membar_release where it's necessary but it never emits any assembly.
I wouldn't expect this to affect performance since it's not emitting an extra instructions but we are emitting some extra barriers which tangles of the memory graph a bit. Could you do some quick performance to make sure nothing's changed?
Otherwise it looks good.
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