Re: [PATCH] Fix WARN_ON / WARN_ON_ONCE regression

From: Jeremy Fitzhardinge
Date: Thu Oct 05 2006 - 17:44:00 EST


Andrew Morton wrote:
So how's this look?

Looks fine to me. Other than the general question of why WARN_ON* returns a value at all, and if so, does the final unlikely() really do anything.

I worry a bit that someone's hardware might go and prefetch that static
variable even when we didn't ask it to. Can that happen?

Sure, the CPU has the option, but if it goes around speculatively polluting its caches with unused stuff, it isn't going to perform very well in general. So presumably the CPU won't do it unless it really thinks it will help.

J
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