mm: page_alloc: simpify page del and expand

When page del from buddy and need expand, it will account free_pages in
zone's migratetype.

The current way is to subtract the page number of the current order when
deleting, and then add it back when expanding.

This is unnecessary, as when migrating the same type, we can directly
record the difference between the high-order pages and the expand added,
and then subtract it directly.

This patch merge that, only when del and expand done, then account
free_pages.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Huan Yang <[email protected]>
Reviewed-by: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions