Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [patch 04/41] cpu ops: Core piece for generic atomic per cpu operations | Date | Fri, 13 Jun 2008 10:38:12 +1000 |
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On Friday 13 June 2008 03:19:51 Christoph Lameter wrote: > Populating the per cpu areas on demand is a good thing especially for > configurations with a large number of processors. If we really go to > support 4k processor by default then we need to allocate the smallest > amount of per cpu structures necessary. Maybe ACPI or so can tell us how > many processors are possible and we only allocate those. But it would be > best if the percpu structures are only allocated for actually active > processors.
cpu_possible_map should definitely be minimal, but your point is well made: dynamic percpu could actually cut memory allocation. If we go for a hybrid scheme where static percpu is always allocated from the initial chunk, however, we still need the current pessimistic overallocation.
Mike's a clever guy, I'm sure he'll think of something :) Rusty.
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