Re: [RFC v2] mm: add page preemption

Kirill A. Shutemov
2019-10-28T12:26:11Z

On Sat, Oct 26, 2019 at 07:28:08PM +0800, Hillf Danton wrote:
> @@ -218,6 +219,9 @@ struct page {
>
> #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
> int _last_cpupid;
> +#else
> + int prio;
> +#define CONFIG_PAGE_PREEMPTION PP
> #endif
> } _struct_page_alignment;
>

No.

There's a really good reason we trying hard to push the _last_cpuid into
page flags instead of growing the struct page by 4 bytes.

I don't think your feature worth 0.1% of RAM and a lot of cache misses
that this change would generate.

--
Kirill A. Shutemov