Messages in this thread | | | Date | Wed, 7 Aug 2013 19:40:15 +0000 | From | Christoph Lameter <> | Subject | Re: [PATCH 04/10] idr: Percpu ida |
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On Wed, 7 Aug 2013, Kent Overstreet wrote:
> I was breaking it apart because I was using this_cpu elsewhere too - for > the bitmap of which cpus have non empty freelists.
this_cpu can be retrieved with smp_processor_id().
> Or is this_cpu_ptr() doing something smarter than per_cpu_ptr(ptr, > smp_processer_id())? There's so many variants I'm not 100% sure they're > the same.
Yes it is. It uses a sepecial register that contains the offset of this cpus per cpu area instead of going through the table of all processor offsets. Its less code.
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