Messages in this thread | | | Date | Thu, 24 Sep 2009 07:03:00 +0900 | From | Tejun Heo <> | Subject | Re: [PATCH 2/4] ia64: allocate percpu area for cpu0 like percpu areas for other cpus |
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Christoph Lameter wrote: > On Wed, 23 Sep 2009, Tejun Heo wrote: > >> any special handling. What problems are you seeing? > > per cpu variable access on IA64 does not use the percpu_offset for the > calculation of the current per cpu data area. Its using a virtual mapping. > > How does the new percpu allocator support this? Does it use different > methods of access for static and dynamic percpu access?
That's only when __ia64_per_cpu_var() macro is used in arch code which always references static perpcu variable in the kernel image which falls inside PERCPU_PAGE_SIZE. For everything else, __my_cpu_offset is defined as __ia64_per_cpu_var(local_per_cpu_offset) and regular pointer offsetting is used.
Thanks.
-- tejun
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