Messages in this thread | | | Date | Fri, 2 Oct 2009 19:32:46 +0200 | From | Ingo Molnar <> | Subject | Re: [this_cpu_xx V4 00/20] Introduce per cpu atomic operations and avoid per cpu address arithmetic |
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* Christoph Lameter <cl@linux-foundation.org> wrote:
> On Fri, 2 Oct 2009, Ingo Molnar wrote: > > > One final step/cleanup seems to be missing from it: it should > > replace current uses of percpu_op() [percpu_read(), etc.] in the x86 > > tree and elsewhere with the new this_cpu_*() primitives. > > this_cpu_*() is using per_cpu_from_op/per_cpu_to_op directly, we > > dont need those percpu_op() variants anymore. > > Well after things settle with this_cpu_xx we can drop those. > > > There should also be a kernel image size comparison done for that > > step, to make sure all the new primitives are optimized to the max > > on the instruction level. > > Right. There will be a time period in which other arches will need to > add support for this_cpu_xx first.
Size comparison should be only on architectures that support it (i.e. x86 right now). The generic fallbacks might be bloaty, no argument about that. ( => the more reason for any architecture to add optimizations for this_cpu_*() APIs. )
Ingo
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