[v7,7/7] mm,page_alloc: Drop unnecessary checks from pfn_range_valid_contig

Commit Message

Oscar Salvador April 13, 2021, 10:47 a.m. UTC

pfn_range_valid_contig() bails out when it finds an in-use page or a
hugetlb page, among other things.
We can drop the in-use page check since __alloc_contig_pages can migrate
away those pages, and the hugetlb page check can go too since
isolate_migratepages_range is now capable of dealing with hugetlb pages.
Either way, those checks are racy so let the end function handle it
when the time comes.

Signed-off-by: Oscar Salvador <[e-mail]>
Suggested-by: David Hildenbrand <[e-mail]>
Reviewed-by: David Hildenbrand <[e-mail]>
---
 mm/page_alloc.c | 6 ------
 1 file changed, 6 deletions(-)

Comments

Mike Kravetz April 13, 2021, 10:53 p.m. UTC | #1

On 4/13/21 3:47 AM, Oscar Salvador wrote:
> pfn_range_valid_contig() bails out when it finds an in-use page or a
> hugetlb page, among other things.
> We can drop the in-use page check since __alloc_contig_pages can migrate
> away those pages, and the hugetlb page check can go too since
> isolate_migratepages_range is now capable of dealing with hugetlb pages.
> Either way, those checks are racy so let the end function handle it
> when the time comes.
> 
> Signed-off-by: Oscar Salvador <[e-mail]>
> Suggested-by: David Hildenbrand <[e-mail]>
> Reviewed-by: David Hildenbrand <[e-mail]>
> ---
>  mm/page_alloc.c | 6 ------
>  1 file changed, 6 deletions(-)

Acked-by: Mike Kravetz <[e-mail]>

Patch

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b5a94de3cdde..c5338e912ace 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -8901,12 +8901,6 @@  static bool pfn_range_valid_contig(struct zone *z, unsigned long start_pfn,
 
 		if (PageReserved(page))
 			return false;
-
-		if (page_count(page) > 0)
-			return false;
-
-		if (PageHuge(page))
-			return false;
 	}
 	return true;
 }