Commit 187df5dd authored by Rik van Riel's avatar Rik van Riel Committed by Linus Torvalds
Browse files

mm,shmem,thp: limit shmem THP allocations to requested zones 

Hugh pointed out that the gma500 driver uses shmem pages, but needs to
limit them to the DMA32 zone.  Ensure the allocations resulting from the
gfp_mask returned by limit_gfp_mask use the zone flags that were
originally passed to shmem_getpage_gfp.

Link: https://lkml.kernel.org/r/20210224121016.1314ed6d@imladris.surriel.com


Signed-off-by: default avatarRik van Riel <riel@surriel.com>
Suggested-by: default avatarHugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xu Yu <xuyu@linux.alibaba.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cd89fb06

mm/shmem.c

+5 −1
Original line number Diff line number Diff line
@@ -1513,7 +1513,11 @@ static gfp_t limit_gfp_mask(gfp_t huge_gfp, gfp_t limit_gfp) 
{

	gfp_t allowflags = __GFP_IO | __GFP_FS | __GFP_RECLAIM;

	gfp_t denyflags = __GFP_NOWARN | __GFP_NORETRY;

	gfp_t result = huge_gfp & ~allowflags;

	gfp_t zoneflags = limit_gfp & GFP_ZONEMASK;

	gfp_t result = huge_gfp & ~(allowflags | GFP_ZONEMASK);



	/* Allow allocations only from the originally specified zones. */

	result |= zoneflags;



	/*

	 * Minimize the result gfp by taking the union with the deny flags,