diff mbox series

[018/118] mm,shmem,thp: limit shmem THP allocations to requested zones

Message ID 20210226011629.y0GUQrjp_%akpm@linux-foundation.org (mailing list archive)
State New
Headers show
Series [001/118] mm: make pagecache tagged lookups return only head pages | expand

Commit Message

Andrew Morton Feb. 26, 2021, 1:16 a.m. UTC
From: Rik van Riel <riel@surriel.com>
Subject: 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: Rik van Riel <riel@surriel.com>
Suggested-by: Hugh 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: Andrew Morton <akpm@linux-foundation.org>
---

 mm/shmem.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

--- a/mm/shmem.c~mmshmemthp-limit-shmem-thp-allocations-to-requested-zones
+++ a/mm/shmem.c
@@ -1513,7 +1513,11 @@  static gfp_t limit_gfp_mask(gfp_t huge_g
 {
 	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,