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SubjectRe: [Use cpuops V1 02/11] vmstat: Optimize zone counter modifications through the use of this cpu operations
On 12/06/2010 06:16 PM, Christoph Lameter wrote:
> this cpu operations can be used to slightly optimize the function. The
> changes will avoid some address calculations and replace them with the
> use of the percpu segment register.
>
> If one would have this_cpu_inc_return and this_cpu_dec_return then it
> would be possible to optimize inc_zone_page_state and dec_zone_page_state even
> more.
>
> V1->V2:
> - Fix __dec_zone_state overflow handling
> - Use s8 variables for temporary storage.
>
> V2->V3:
> - Put __percpu annotations in correct places.
>
> Reviewed-by: Pekka Enberg <penberg@kernel.org>
> Signed-off-by: Christoph Lameter <cl@linux.com>

> @@ -221,16 +223,19 @@ EXPORT_SYMBOL(mod_zone_page_state);
...
> + __this_cpu_write(*p, - overstep);

Applied to percpu#for-next with the space after '-' removed from the
above line.

Thanks.

--
tejun


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