Re: [RFC 0/2] srcu: Remove pre-flip memory barrier

Mathieu Desnoyers
2022-12-20T19:01:28Z

On 2022-12-20 13:29, Joel Fernandes wrote:
>

> I do want to finish my memory barrier studies of SRCU over the holidays since I have been deep in the hole with that already. Back to the post flip memory barrier here since I think now even that might not be needed…

I strongly suspect the memory barrier after flip is useless for the same
reasons I mentioned explaining why the barrier before the flip is useless.

However, we need to double-check that we have memory barriers at the
beginning and end of synchronize_srcu, and between load of "unlock"
counters and load of "lock" counters.

Where is the barrier at the beginning of synchronize_srcu ?

Thanks,

Mathieu

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Mathieu Desnoyers
EfficiOS Inc.