Messages in this thread | | | Date | Tue, 17 Jun 2014 14:39:46 -0500 (CDT) | From | Christoph Lameter <> | Subject | Re: [PATCH RFC] percpu: add data dependency barrier in percpu accessors and operations |
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On Tue, 17 Jun 2014, Paul E. McKenney wrote:
> We are talking about one CPU initializing all CPUs' portions of > dynamically allocated per-CPU memory, so there really is more than > one CPU involved.
Well that only occurs on initialization before the address of the struct that contains the offset is available to other processors.
During operation the percpu area functions like a single processor. And its designed that way to avoid synchronization issues and take full advantage of *no* synchronization for full speed. We compromise on that for statistics but that is only read access.
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