Messages in this thread | | | Date | Tue, 24 Feb 2009 23:40:43 +0900 | From | Tejun Heo <> | Subject | Re: [PATCHSET x86/core/percpu] improve the first percpu chunk allocation |
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Hello, Ingo.
Ingo Molnar wrote: > * Tejun Heo <tj@kernel.org> wrote: > >>> and i think that abstraction is wrong. >> No, it's not wrong. It simply is irrelevant - it's congruent >> vs. contiguos and all that we need is congruent. Contiguous >> of course achieves congruent but it doesn't make any >> difference for this purpose. > > Well, as long as we can go up in unit size to 2MB (on 64-bit > x86) i'm fine with that model.
Yeap, it defintely can.
> There's no granularity artifacts, right? pcpu_populate_chunk() > intelligently only populates pages on an as-needed basis, so > extending the percpu areas with a 2MB unit does not trigger > nr_cpus*2MB allocations straight away.
Yeap, it doesn't although reclamation is done per-chunk currently.
> The code looks very clean and if we can agree on the SMP/NUMA > symmetry and the dynamic-ptr optimizations that it allows, plus > if you can up the unit size to 2MB on 64-bit x86, i'm a happy > camper and will pull it.
Sounds good. Thanks.
-- tejun
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