Re: [PATCH] synchronize_irq needs a barrier

From: Herbert Xu
Date: Thu Oct 18 2007 - 10:36:41 EST


Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> Note that some kind of read barrier or compiler barrier should be needed
> regardless, or we are just not sync'ing with anything at all (we may
> have loaded the value ages ago and thus operate on a totally stale
> value). I prefer a full barrier to also ensure all previous stores are
> pushed out.

We already have a compiler barrier there in the form of cpu_relax.

Cheers,
--
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