[PATCH 2/2] mm: memcontrol: switch to native NR_VMALLOC vmstat counter

[Johannes Weiner <hannes@cmpxchg.org>]

Eliminates the custom memcg counter and results in a single,
consolidated accounting call in vmalloc code.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
---
 include/linux/memcontrol.h |  1 -
 mm/memcontrol.c            |  4 ++--
 mm/vmalloc.c               | 16 ++++------------
 3 files changed, 6 insertions(+), 15 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 67f154de10bc..c7cc4e50e59a 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -35,7 +35,6 @@ enum memcg_stat_item {
 	MEMCG_SWAP = NR_VM_NODE_STAT_ITEMS,
 	MEMCG_SOCK,
 	MEMCG_PERCPU_B,
-	MEMCG_VMALLOC,
 	MEMCG_KMEM,
 	MEMCG_ZSWAP_B,
 	MEMCG_ZSWAPPED,
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 129eed3ff5bb..fef5bdd887e0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -317,6 +317,7 @@ static const unsigned int memcg_node_stat_items[] = {
 	NR_SHMEM_THPS,
 	NR_FILE_THPS,
 	NR_ANON_THPS,
+	NR_VMALLOC,
 	NR_KERNEL_STACK_KB,
 	NR_PAGETABLE,
 	NR_SECONDARY_PAGETABLE,
@@ -339,7 +340,6 @@ static const unsigned int memcg_stat_items[] = {
 	MEMCG_SWAP,
 	MEMCG_SOCK,
 	MEMCG_PERCPU_B,
-	MEMCG_VMALLOC,
 	MEMCG_KMEM,
 	MEMCG_ZSWAP_B,
 	MEMCG_ZSWAPPED,
@@ -1359,7 +1359,7 @@ static const struct memory_stat memory_stats[] = {
 	{ "sec_pagetables",		NR_SECONDARY_PAGETABLE		},
 	{ "percpu",			MEMCG_PERCPU_B			},
 	{ "sock",			MEMCG_SOCK			},
-	{ "vmalloc",			MEMCG_VMALLOC			},
+	{ "vmalloc",			NR_VMALLOC			},
 	{ "shmem",			NR_SHMEM			},
 #ifdef CONFIG_ZSWAP
 	{ "zswap",			MEMCG_ZSWAP_B			},
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index a49a46de9c4f..8773bc0c4734 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -3446,9 +3446,6 @@ void vfree(const void *addr)
 
 	if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS))
 		vm_reset_perms(vm);
-	/* All pages of vm should be charged to same memcg, so use first one. */
-	if (vm->nr_pages && !(vm->flags & VM_MAP_PUT_PAGES))
-		mod_memcg_page_state(vm->pages[0], MEMCG_VMALLOC, -vm->nr_pages);
 	for (i = 0; i < vm->nr_pages; i++) {
 		struct page *page = vm->pages[i];
 
@@ -3458,7 +3455,7 @@ void vfree(const void *addr)
 		 * can be freed as an array of order-0 allocations
 		 */
 		if (!(vm->flags & VM_MAP_PUT_PAGES))
-			dec_node_page_state(page, NR_VMALLOC);
+			mod_lruvec_page_state(page, NR_VMALLOC, -1);
 		__free_page(page);
 		cond_resched();
 	}
@@ -3649,7 +3646,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
 			continue;
 		}
 
-		mod_node_page_state(page, NR_VMALLOC, 1 << large_order);
+		mod_lruvec_page_state(page, NR_VMALLOC, 1 << large_order);
 
 		split_page(page, large_order);
 		for (i = 0; i < (1U << large_order); i++)
@@ -3696,7 +3693,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
 							pages + nr_allocated);
 
 			for (i = nr_allocated; i < nr_allocated + nr; i++)
-				inc_node_page_state(pages[i], NR_VMALLOC);
+				mod_lruvec_page_state(pages[i], NR_VMALLOC, 1);
 
 			nr_allocated += nr;
 
@@ -3722,7 +3719,7 @@ vm_area_alloc_pages(gfp_t gfp, int nid,
 		if (unlikely(!page))
 			break;
 
-		mod_node_page_state(page, NR_VMALLOC, 1 << order);
+		mod_lruvec_page_state(page, NR_VMALLOC, 1 << order);
 
 		/*
 		 * High-order allocations must be able to be treated as
@@ -3866,11 +3863,6 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
 			vmalloc_gfp_adjust(gfp_mask, page_order), node,
 			page_order, nr_small_pages, area->pages);
 
-	/* All pages of vm should be charged to same memcg, so use first one. */
-	if (gfp_mask & __GFP_ACCOUNT && area->nr_pages)
-		mod_memcg_page_state(area->pages[0], MEMCG_VMALLOC,
-				     area->nr_pages);
-
 	/*
 	 * If not enough pages were obtained to accomplish an
 	 * allocation request, free them via vfree() if any.
-- 
2.53.0