Messages in this thread |  | | | From | (Eric W. Biederman) | | Date | Thu, 10 Jul 2008 12:18:25 -0700 | | Subject | Re: [RFC 00/15] x86_64: Optimize percpu accesses |
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Jeremy Fitzhardinge <jeremy@goop.org> writes:
> Eric W. Biederman wrote: >> I think we can get away with just simply realloc'ing the percpu area >> on each cpu. No fancy table manipulations required. Just update >> the base pointer in %gs and in someplace global. >> > > It's perfectly legitimate to take the address of a percpu variable and store it > somewhere. We can't move them around.
Really? I guess there are cases where that makes sense. It is a pretty rare case though. Especially when you are not talking about doing it temporarily with preemption disabled. There are few enough users of the API I think we can certainly explore the cost of forbidding in the general case of storing the address of a percpu variable.
Eric
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