Re: [RFC v2 PATCH 4/4] mm: pre zero out free pages to speed up page allocation for __GFP_ZERO

[Dave Hansen]

On 12/21/20 8:30 AM, Liang Li wrote:
> --- a/include/linux/page-flags.h
> +++ b/include/linux/page-flags.h
> @@ -137,6 +137,9 @@ enum pageflags {
>  #endif
>  #ifdef CONFIG_64BIT
>  	PG_arch_2,
> +#endif
> +#ifdef CONFIG_PREZERO_PAGE
> +	PG_zero,
>  #endif
>  	__NR_PAGEFLAGS,

I don't think this is worth a generic page->flags bit.

There's a ton of space in 'struct page' for pages that are in the
allocator.  Can't we use some of that space?