Re: [PATCH] mm: Increase folio batch size

["Garg, Shivank" <shivankg@amd.com>]

>  include/linux/pagevec.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h
> index fcc06c300a72..5d3a0cccc6bf 100644
> --- a/include/linux/pagevec.h
> +++ b/include/linux/pagevec.h
> @@ -11,8 +11,8 @@
>  
>  #include <linux/types.h>
>  
> -/* 15 pointers + header align the folio_batch structure to a power of two */
> -#define PAGEVEC_SIZE	15
> +/* 31 pointers + header align the folio_batch structure to a power of two */
> +#define PAGEVEC_SIZE	31
>  
>  struct folio;
>  

Hi,

Thanks for the patch.
I tested the patch with will-it-scale page-fault2 on AMD Zen 4 EPYC server (2-socket system with 128 cores per socket, SMT Enabled). 

Increasing the folio batch size from 15 to 31 gives following performance improvement:
Median: 8.32% 
Max: 23.15%
99th percentile: 20.95%

There is slight performance degradation (bound by -1.21%) in a few cases.

The patch seems to be beneficial for AMD systems as well.

Tested-by: Shivank Garg <shivankg@amd.com>

--
Best Regards,
Shivank