[PATCH 2/2] mm: get rid of __GFP_OTHER_NODE

[Michal Hocko]

From: Michal Hocko <mhocko@xxxxxxxx>

The flag has been introduced by 78afd5612deb ("mm: add __GFP_OTHER_NODE
flag") to allow proper accounting of remote node allocations done by
kernel daemons on behalf of a process - e.g. khugepaged.

After "mm: fix remote numa hits statistics" we do not need and actually
use the flag so we can safely remove it because all allocations which
are satisfied from their "home" node are accounted properly.

Acked-by: Mel Gorman <mgorman@xxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
---
 include/linux/gfp.h            | 13 +++----------
 include/trace/events/mmflags.h |  1 -
 mm/huge_memory.c               |  3 +--
 mm/khugepaged.c                |  5 ++---
 mm/page_alloc.c                |  5 ++---
 tools/perf/builtin-kmem.c      |  1 -
 6 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 4175dca4ac39..7806a8f80abc 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -38,9 +38,8 @@ struct vm_area_struct;
 #define ___GFP_ACCOUNT		0x100000u
 #define ___GFP_NOTRACK		0x200000u
 #define ___GFP_DIRECT_RECLAIM	0x400000u
-#define ___GFP_OTHER_NODE	0x800000u
-#define ___GFP_WRITE		0x1000000u
-#define ___GFP_KSWAPD_RECLAIM	0x2000000u
+#define ___GFP_WRITE		0x800000u
+#define ___GFP_KSWAPD_RECLAIM	0x1000000u
 /* If the above are modified, __GFP_BITS_SHIFT may need updating */
 
 /*
@@ -172,11 +171,6 @@ struct vm_area_struct;
  * __GFP_NOTRACK_FALSE_POSITIVE is an alias of __GFP_NOTRACK. It's a means of
  *   distinguishing in the source between false positives and allocations that
  *   cannot be supported (e.g. page tables).
- *
- * __GFP_OTHER_NODE is for allocations that are on a remote node but that
- *   should not be accounted for as a remote allocation in vmstat. A
- *   typical user would be khugepaged collapsing a huge page on a remote
- *   node.
  */
 #define __GFP_COLD	((__force gfp_t)___GFP_COLD)
 #define __GFP_NOWARN	((__force gfp_t)___GFP_NOWARN)
@@ -184,10 +178,9 @@ struct vm_area_struct;
 #define __GFP_ZERO	((__force gfp_t)___GFP_ZERO)
 #define __GFP_NOTRACK	((__force gfp_t)___GFP_NOTRACK)
 #define __GFP_NOTRACK_FALSE_POSITIVE (__GFP_NOTRACK)
-#define __GFP_OTHER_NODE ((__force gfp_t)___GFP_OTHER_NODE)
 
 /* Room for N __GFP_FOO bits */
-#define __GFP_BITS_SHIFT 26
+#define __GFP_BITS_SHIFT 25
 #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
 
 /*
diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h
index 5a81ab48a2fb..556a0efa8298 100644
--- a/include/trace/events/mmflags.h
+++ b/include/trace/events/mmflags.h
@@ -48,7 +48,6 @@
 	{(unsigned long)__GFP_RECLAIM,		"__GFP_RECLAIM"},	\
 	{(unsigned long)__GFP_DIRECT_RECLAIM,	"__GFP_DIRECT_RECLAIM"},\
 	{(unsigned long)__GFP_KSWAPD_RECLAIM,	"__GFP_KSWAPD_RECLAIM"},\
-	{(unsigned long)__GFP_OTHER_NODE,	"__GFP_OTHER_NODE"}	\
 
 #define show_gfp_flags(flags)						\
 	(flags) ? __print_flags(flags, "|",				\
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index f3c2040edbb1..8206abf4ac03 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -918,8 +918,7 @@ static int do_huge_pmd_wp_page_fallback(struct vm_fault *vmf, pmd_t orig_pmd,
 	}
 
 	for (i = 0; i < HPAGE_PMD_NR; i++) {
-		pages[i] = alloc_page_vma_node(GFP_HIGHUSER_MOVABLE |
-					       __GFP_OTHER_NODE, vma,
+		pages[i] = alloc_page_vma_node(GFP_HIGHUSER_MOVABLE, vma,
 					       vmf->address, page_to_nid(page));
 		if (unlikely(!pages[i] ||
 			     mem_cgroup_try_charge(pages[i], vma->vm_mm,
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index e32389a97030..211974a3992b 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -943,7 +943,7 @@ static void collapse_huge_page(struct mm_struct *mm,
 	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
 
 	/* Only allocate from the target node */
-	gfp = alloc_hugepage_khugepaged_gfpmask() | __GFP_OTHER_NODE | __GFP_THISNODE;
+	gfp = alloc_hugepage_khugepaged_gfpmask() | __GFP_THISNODE;
 
 	/*
 	 * Before allocating the hugepage, release the mmap_sem read lock.
@@ -1326,8 +1326,7 @@ static void collapse_shmem(struct mm_struct *mm,
 	VM_BUG_ON(start & (HPAGE_PMD_NR - 1));
 
 	/* Only allocate from the target node */
-	gfp = alloc_hugepage_khugepaged_gfpmask() |
-		__GFP_OTHER_NODE | __GFP_THISNODE;
+	gfp = alloc_hugepage_khugepaged_gfpmask() | __GFP_THISNODE;
 
 	new_page = khugepaged_alloc_page(hpage, gfp, node);
 	if (!new_page) {
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e2a44950a685..ea60dc06d280 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2584,8 +2584,7 @@ int __isolate_free_page(struct page *page, unsigned int order)
  *
  * Must be called with interrupts disabled.
  */
-static inline void zone_statistics(struct zone *preferred_zone, struct zone *z,
-								gfp_t flags)
+static inline void zone_statistics(struct zone *preferred_zone, struct zone *z)
 {
 #ifdef CONFIG_NUMA
 	enum zone_stat_item local_stat = NUMA_LOCAL;
@@ -2667,7 +2666,7 @@ struct page *buffered_rmqueue(struct zone *preferred_zone,
 	}
 
 	__count_zid_vm_events(PGALLOC, page_zonenum(page), 1 << order);
-	zone_statistics(preferred_zone, zone, gfp_flags);
+	zone_statistics(preferred_zone, zone);
 	local_irq_restore(flags);
 
 	VM_BUG_ON_PAGE(bad_range(zone, page), page);
diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index d426dcb18ce9..33b959d47545 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -645,7 +645,6 @@ static const struct {
 	{ "__GFP_RECLAIM",		"R" },
 	{ "__GFP_DIRECT_RECLAIM",	"DR" },
 	{ "__GFP_KSWAPD_RECLAIM",	"KR" },
-	{ "__GFP_OTHER_NODE",		"ON" },
 };
 
 static size_t max_gfp_len;
-- 
2.11.0