Re: [PATCH v8 15/19] locking/rwsem: Adaptive disabling of reader optimistic spinning

[Peter Zijlstra]

On Mon, May 20, 2019 at 04:59:14PM -0400, Waiman Long wrote:
> On a 2-socket 40-core 80-thread Skylake system, the page_fault1 test of
> the will-it-scale benchmark was run with various number of threads. The
> number of operations done before reader optimistic spinning patches,
> this patch and after this patch were:
> 
>   Threads  Before rspin  Before patch  After patch    %change
>   -------  ------------  ------------  -----------    -------
>     20        5541068      5345484       5455667    -3.5%/ +2.1%
>     40       10185150      7292313       9219276   -28.5%/+26.4%
>     60        8196733      6460517       7181209   -21.2%/+11.2%
>     80        9508864      6739559       8107025   -29.1%/+20.3%

'rspin' is patch 12 in this series, right?