Re: [PATCH mmotm v2] mm: delete __ClearPageWaiters()

From: David Hildenbrand
Date: Mon Mar 07 2022 - 03:41:26 EST


On 04.03.22 22:25, Hugh Dickins wrote:
> The PG_waiters bit is not included in PAGE_FLAGS_CHECK_AT_FREE, and
> vmscan.c's free_unref_page_list() callers rely on that not to generate
> bad_page() alerts. So __page_cache_release(), put_pages_list() and
> release_pages() (and presumably copy-and-pasted free_zone_device_page())
> are redundant and misleading to make a special point of clearing it (as
> the "__" implies, it could only safely be used on the freeing path).
>
> Delete __ClearPageWaiters(). Remark on this in one of the "possible"
> comments in folio_wake_bit(), and delete the superfluous comments.
>
> Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
> Tested-by: Yu Zhao <yuzhao@xxxxxxxxxx>

Thanks

Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>


--
Thanks,

David / dhildenb