+ mmshmemthp-limit-shmem-thp-allocations-to-requested-zones.patch added to -mm tree

+ mmshmemthp-limit-shmem-thp-allocations-to-requested-zones.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm,shmem,thp: limit shmem THP allocations to requested zones
has been added to the -mm tree.  Its filename is
     mmshmemthp-limit-shmem-thp-allocations-to-requested-zones.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mmshmemthp-limit-shmem-thp-allocations-to-requested-zones.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mmshmemthp-limit-shmem-thp-allocations-to-requested-zones.patch

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------------------------------------------------------
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(-)

--- 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,
_

Patches currently in -mm which might be from riel@surriel.com are

mmthpshmem-limit-shmem-thp-alloc-gfp_mask.patch
mmthpshm-limit-gfp-mask-to-no-more-than-specified.patch
mmthpshmem-make-khugepaged-obey-tmpfs-mount-flags.patch
mmshmemthp-limit-shmem-thp-allocations-to-requested-zones.patch