mm: introduce new field "managed_pages" to struct zone

[Simon Jeons <simon.jeons@xxxxxxxxx>]

Hi Jiang,

https://patchwork.kernel.org/patch/1781291/

You said that the bootmem allocator doesn't touch *highmem pages*, so highmem zones' managed_pages is set to the accurate value "spanned_pages - absent_pages" in function free_area_init_core() and won't be updated anymore. Why it doesn't touch *highmem pages*? Could you point out where you figure out this?