Re: [PATCH 06/28] mm, page_alloc: Use __dec_zone_state for order-0 page allocation

[Vlastimil Babka]

On 04/15/2016 10:58 AM, Mel Gorman wrote:
> __dec_zone_state is cheaper to use for removing an order-0 page as it
> has fewer conditions to check.
>
> The performance difference on a page allocator microbenchmark is;
>
>                                             4.6.0-rc2                  4.6.0-rc2
>                                         optiter-v1r20              decstat-v1r20
> Min      alloc-odr0-1               382.00 (  0.00%)           381.00 (  0.26%)
> Min      alloc-odr0-2               282.00 (  0.00%)           275.00 (  2.48%)
> Min      alloc-odr0-4               233.00 (  0.00%)           229.00 (  1.72%)
> Min      alloc-odr0-8               203.00 (  0.00%)           199.00 (  1.97%)
> Min      alloc-odr0-16              188.00 (  0.00%)           186.00 (  1.06%)
> Min      alloc-odr0-32              182.00 (  0.00%)           179.00 (  1.65%)
> Min      alloc-odr0-64              177.00 (  0.00%)           174.00 (  1.69%)
> Min      alloc-odr0-128             175.00 (  0.00%)           172.00 (  1.71%)
> Min      alloc-odr0-256             184.00 (  0.00%)           181.00 (  1.63%)
> Min      alloc-odr0-512             197.00 (  0.00%)           193.00 (  2.03%)
> Min      alloc-odr0-1024            203.00 (  0.00%)           201.00 (  0.99%)
> Min      alloc-odr0-2048            209.00 (  0.00%)           206.00 (  1.44%)
> Min      alloc-odr0-4096            214.00 (  0.00%)           212.00 (  0.93%)
> Min      alloc-odr0-8192            218.00 (  0.00%)           215.00 (  1.38%)
> Min      alloc-odr0-16384           219.00 (  0.00%)           216.00 (  1.37%)
>
> Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>

Acked-by: Vlastimil Babka <vbabka@xxxxxxx>