mm,page_owner: implement the tracking of the stacks count

mm,page_owner: implement the tracking of the stacks count

Implement {inc,dec}_stack_record_count() which increments or decrements on
respective allocation and free operations, via __reset_page_owner() (free
operation) and __set_page_owner() (alloc operation).

Newly allocated stack_record structs will be added to the list stack_list
via add_stack_record_to_list().  Modifications on the list are protected
via a spinlock with irqs disabled, since this code can also be reached
from IRQ context.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Oscar Salvador <[email protected]>
Reviewed-by: Marco Elver <[email protected]>
Reviewed-by: Vlastimil Babka <[email protected]>
Acked-by: Andrey Konovalov <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>