mm: memcontrol: re-use node VM page state enum

The current duplication is a high-maintenance mess, and it's painful to
add new items or query memcg state from the rest of the VM.

This increases the size of the stat array marginally, but we should aim
to track all these stats on a per-cgroup level anyway.

Link: http://lkml.kernel.org/r/20170404220148.28338-3-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 80 insertions, 81 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6b42887e5f14..6fe4c7fafbfc 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -100,18 +100,7 @@ static bool do_memsw_account(void)
 	return !cgroup_subsys_on_dfl(memory_cgrp_subsys) && do_swap_account;
 }
 
-static const char * const mem_cgroup_stat_names[] = {
-	"cache",
-	"rss",
-	"rss_huge",
-	"shmem",
-	"mapped_file",
-	"dirty",
-	"writeback",
-	"swap",
-};
-
-static const char * const mem_cgroup_lru_names[] = {
+static const char *const mem_cgroup_lru_names[] = {
 	"inactive_anon",
 	"active_anon",
 	"inactive_file",
@@ -583,20 +572,16 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg,
 	 * counted as CACHE even if it's on ANON LRU.
 	 */
 	if (PageAnon(page))
-		__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS],
-				nr_pages);
+		__this_cpu_add(memcg->stat->count[MEMCG_RSS], nr_pages);
 	else {
-		__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_CACHE],
-				nr_pages);
+		__this_cpu_add(memcg->stat->count[MEMCG_CACHE], nr_pages);
 		if (PageSwapBacked(page))
-			__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SHMEM],
-				       nr_pages);
+			__this_cpu_add(memcg->stat->count[NR_SHMEM], nr_pages);
 	}
 
 	if (compound) {
 		VM_BUG_ON_PAGE(!PageTransHuge(page), page);
-		__this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
-				nr_pages);
+		__this_cpu_add(memcg->stat->count[MEMCG_RSS_HUGE], nr_pages);
 	}
 
 	/* pagein of a big page is an event. So, ignore page size */
@@ -1125,6 +1110,28 @@ static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
 	return false;
 }
 
+unsigned int memcg1_stats[] = {
+	MEMCG_CACHE,
+	MEMCG_RSS,
+	MEMCG_RSS_HUGE,
+	NR_SHMEM,
+	NR_FILE_MAPPED,
+	NR_FILE_DIRTY,
+	NR_WRITEBACK,
+	MEMCG_SWAP,
+};
+
+static const char *const memcg1_stat_names[] = {
+	"cache",
+	"rss",
+	"rss_huge",
+	"shmem",
+	"mapped_file",
+	"dirty",
+	"writeback",
+	"swap",
+};
+
 #define K(x) ((x) << (PAGE_SHIFT-10))
 /**
  * mem_cgroup_print_oom_info: Print OOM information relevant to memory controller.
@@ -1169,11 +1176,11 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 		pr_cont_cgroup_path(iter->css.cgroup);
 		pr_cont(":");
 
-		for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
-			if (i == MEM_CGROUP_STAT_SWAP && !do_swap_account)
+		for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
+			if (memcg1_stats[i] == MEMCG_SWAP && !do_swap_account)
 				continue;
-			pr_cont(" %s:%luKB", mem_cgroup_stat_names[i],
-				K(mem_cgroup_read_stat(iter, i)));
+			pr_cont(" %s:%luKB", memcg1_stat_names[i],
+				K(mem_cgroup_read_stat(iter, memcg1_stats[i])));
 		}
 
 		for (i = 0; i < NR_LRU_LISTS; i++)
@@ -2362,7 +2369,7 @@ void mem_cgroup_split_huge_fixup(struct page *head)
 	for (i = 1; i < HPAGE_PMD_NR; i++)
 		head[i].mem_cgroup = head->mem_cgroup;
 
-	__this_cpu_sub(head->mem_cgroup->stat->count[MEM_CGROUP_STAT_RSS_HUGE],
+	__this_cpu_sub(head->mem_cgroup->stat->count[MEMCG_RSS_HUGE],
 		       HPAGE_PMD_NR);
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
@@ -2372,7 +2379,7 @@ static void mem_cgroup_swap_statistics(struct mem_cgroup *memcg,
 					 bool charge)
 {
 	int val = (charge) ? 1 : -1;
-	this_cpu_add(memcg->stat->count[MEM_CGROUP_STAT_SWAP], val);
+	this_cpu_add(memcg->stat->count[MEMCG_SWAP], val);
 }
 
 /**
@@ -2731,13 +2738,10 @@ static unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
 		struct mem_cgroup *iter;
 
 		for_each_mem_cgroup_tree(iter, memcg) {
-			val += mem_cgroup_read_stat(iter,
-					MEM_CGROUP_STAT_CACHE);
-			val += mem_cgroup_read_stat(iter,
-					MEM_CGROUP_STAT_RSS);
+			val += mem_cgroup_read_stat(iter, MEMCG_CACHE);
+			val += mem_cgroup_read_stat(iter, MEMCG_RSS);
 			if (swap)
-				val += mem_cgroup_read_stat(iter,
-						MEM_CGROUP_STAT_SWAP);
+				val += mem_cgroup_read_stat(iter, MEMCG_SWAP);
 		}
 	} else {
 		if (!swap)
@@ -3134,15 +3138,15 @@ static int memcg_stat_show(struct seq_file *m, void *v)
 	struct mem_cgroup *mi;
 	unsigned int i;
 
-	BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_stat_names) !=
-		     MEM_CGROUP_STAT_NSTATS);
+	BUILD_BUG_ON(ARRAY_SIZE(memcg1_stat_names) != ARRAY_SIZE(memcg1_stats));
 	BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS);
 
-	for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
-		if (i == MEM_CGROUP_STAT_SWAP && !do_memsw_account())
+	for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
+		if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account())
 			continue;
-		seq_printf(m, "%s %lu\n", mem_cgroup_stat_names[i],
-			   mem_cgroup_read_stat(memcg, i) * PAGE_SIZE);
+		seq_printf(m, "%s %lu\n", memcg1_stat_names[i],
+			   mem_cgroup_read_stat(memcg, memcg1_stats[i]) *
+			   PAGE_SIZE);
 	}
 
 	for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
@@ -3165,14 +3169,15 @@ static int memcg_stat_show(struct seq_file *m, void *v)
 		seq_printf(m, "hierarchical_memsw_limit %llu\n",
 			   (u64)memsw * PAGE_SIZE);
 
-	for (i = 0; i < MEM_CGROUP_STAT_NSTATS; i++) {
+	for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
 		unsigned long long val = 0;
 
-		if (i == MEM_CGROUP_STAT_SWAP && !do_memsw_account())
+		if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account())
 			continue;
 		for_each_mem_cgroup_tree(mi, memcg)
-			val += mem_cgroup_read_stat(mi, i) * PAGE_SIZE;
-		seq_printf(m, "total_%s %llu\n", mem_cgroup_stat_names[i], val);
+			val += mem_cgroup_read_stat(mi, memcg1_stats[i]) *
+			PAGE_SIZE;
+		seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i], val);
 	}
 
 	for (i = 0; i < ARRAY_SIZE(memcg1_events); i++) {
@@ -3645,10 +3650,10 @@ void mem_cgroup_wb_stats(struct bdi_writeback *wb, unsigned long *pfilepages,
 	struct mem_cgroup *memcg = mem_cgroup_from_css(wb->memcg_css);
 	struct mem_cgroup *parent;
 
-	*pdirty = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_DIRTY);
+	*pdirty = mem_cgroup_read_stat(memcg, NR_FILE_DIRTY);
 
 	/* this should eventually include NR_UNSTABLE_NFS */
-	*pwriteback = mem_cgroup_read_stat(memcg, MEM_CGROUP_STAT_WRITEBACK);
+	*pwriteback = mem_cgroup_read_stat(memcg, NR_WRITEBACK);
 	*pfilepages = mem_cgroup_nr_lru_pages(memcg, (1 << LRU_INACTIVE_FILE) |
 						     (1 << LRU_ACTIVE_FILE));
 	*pheadroom = PAGE_COUNTER_MAX;
@@ -4504,10 +4509,8 @@ static int mem_cgroup_move_account(struct page *page,
 	spin_lock_irqsave(&from->move_lock, flags);
 
 	if (!anon && page_mapped(page)) {
-		__this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
-			       nr_pages);
-		__this_cpu_add(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED],
-			       nr_pages);
+		__this_cpu_sub(from->stat->count[NR_FILE_MAPPED], nr_pages);
+		__this_cpu_add(to->stat->count[NR_FILE_MAPPED], nr_pages);
 	}
 
 	/*
@@ -4519,18 +4522,16 @@ static int mem_cgroup_move_account(struct page *page,
 		struct address_space *mapping = page_mapping(page);
 
 		if (mapping_cap_account_dirty(mapping)) {
-			__this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_DIRTY],
+			__this_cpu_sub(from->stat->count[NR_FILE_DIRTY],
 				       nr_pages);
-			__this_cpu_add(to->stat->count[MEM_CGROUP_STAT_DIRTY],
+			__this_cpu_add(to->stat->count[NR_FILE_DIRTY],
 				       nr_pages);
 		}
 	}
 
 	if (PageWriteback(page)) {
-		__this_cpu_sub(from->stat->count[MEM_CGROUP_STAT_WRITEBACK],
-			       nr_pages);
-		__this_cpu_add(to->stat->count[MEM_CGROUP_STAT_WRITEBACK],
-			       nr_pages);
+		__this_cpu_sub(from->stat->count[NR_WRITEBACK], nr_pages);
+		__this_cpu_add(to->stat->count[NR_WRITEBACK], nr_pages);
 	}
 
 	/*
@@ -5190,9 +5191,9 @@ static int memory_stat_show(struct seq_file *m, void *v)
 	tree_events(memcg, events);
 
 	seq_printf(m, "anon %llu\n",
-		   (u64)stat[MEM_CGROUP_STAT_RSS] * PAGE_SIZE);
+		   (u64)stat[MEMCG_RSS] * PAGE_SIZE);
 	seq_printf(m, "file %llu\n",
-		   (u64)stat[MEM_CGROUP_STAT_CACHE] * PAGE_SIZE);
+		   (u64)stat[MEMCG_CACHE] * PAGE_SIZE);
 	seq_printf(m, "kernel_stack %llu\n",
 		   (u64)stat[MEMCG_KERNEL_STACK_KB] * 1024);
 	seq_printf(m, "slab %llu\n",
@@ -5202,13 +5203,13 @@ static int memory_stat_show(struct seq_file *m, void *v)
 		   (u64)stat[MEMCG_SOCK] * PAGE_SIZE);
 
 	seq_printf(m, "shmem %llu\n",
-		   (u64)stat[MEM_CGROUP_STAT_SHMEM] * PAGE_SIZE);
+		   (u64)stat[NR_SHMEM] * PAGE_SIZE);
 	seq_printf(m, "file_mapped %llu\n",
-		   (u64)stat[MEM_CGROUP_STAT_FILE_MAPPED] * PAGE_SIZE);
+		   (u64)stat[NR_FILE_MAPPED] * PAGE_SIZE);
 	seq_printf(m, "file_dirty %llu\n",
-		   (u64)stat[MEM_CGROUP_STAT_DIRTY] * PAGE_SIZE);
+		   (u64)stat[NR_FILE_DIRTY] * PAGE_SIZE);
 	seq_printf(m, "file_writeback %llu\n",
-		   (u64)stat[MEM_CGROUP_STAT_WRITEBACK] * PAGE_SIZE);
+		   (u64)stat[NR_WRITEBACK] * PAGE_SIZE);
 
 	for (i = 0; i < NR_LRU_LISTS; i++) {
 		struct mem_cgroup *mi;
@@ -5231,11 +5232,11 @@ static int memory_stat_show(struct seq_file *m, void *v)
 	seq_printf(m, "pgmajfault %lu\n", events[PGMAJFAULT]);
 
 	seq_printf(m, "workingset_refault %lu\n",
-		   stat[MEMCG_WORKINGSET_REFAULT]);
+		   stat[WORKINGSET_REFAULT]);
 	seq_printf(m, "workingset_activate %lu\n",
-		   stat[MEMCG_WORKINGSET_ACTIVATE]);
+		   stat[WORKINGSET_ACTIVATE]);
 	seq_printf(m, "workingset_nodereclaim %lu\n",
-		   stat[MEMCG_WORKINGSET_NODERECLAIM]);
+		   stat[WORKINGSET_NODERECLAIM]);
 
 	return 0;
 }
@@ -5492,10 +5493,10 @@ static void uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout,
 	}
 
 	local_irq_save(flags);
-	__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS], nr_anon);
-	__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_CACHE], nr_file);
-	__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_RSS_HUGE], nr_huge);
-	__this_cpu_sub(memcg->stat->count[MEM_CGROUP_STAT_SHMEM], nr_shmem);
+	__this_cpu_sub(memcg->stat->count[MEMCG_RSS], nr_anon);
+	__this_cpu_sub(memcg->stat->count[MEMCG_CACHE], nr_file);
+	__this_cpu_sub(memcg->stat->count[MEMCG_RSS_HUGE], nr_huge);
+	__this_cpu_sub(memcg->stat->count[NR_SHMEM], nr_shmem);
 	__this_cpu_add(memcg->stat->events[PGPGOUT], pgpgout);
 	__this_cpu_add(memcg->stat->nr_page_events, nr_pages);
 	memcg_check_events(memcg, dummy_page);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 33df0583edb9..777711203809 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2427,7 +2427,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping)
 		inode_attach_wb(inode, page);
 		wb = inode_to_wb(inode);
 
-		mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_DIRTY);
+		mem_cgroup_inc_page_stat(page, NR_FILE_DIRTY);
 		__inc_node_page_state(page, NR_FILE_DIRTY);
 		__inc_zone_page_state(page, NR_ZONE_WRITE_PENDING);
 		__inc_node_page_state(page, NR_DIRTIED);
@@ -2449,7 +2449,7 @@ void account_page_cleaned(struct page *page, struct address_space *mapping,
 			  struct bdi_writeback *wb)
 {
 	if (mapping_cap_account_dirty(mapping)) {
-		mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_DIRTY);
+		mem_cgroup_dec_page_stat(page, NR_FILE_DIRTY);
 		dec_node_page_state(page, NR_FILE_DIRTY);
 		dec_zone_page_state(page, NR_ZONE_WRITE_PENDING);
 		dec_wb_stat(wb, WB_RECLAIMABLE);
@@ -2706,7 +2706,7 @@ int clear_page_dirty_for_io(struct page *page)
 		 */
 		wb = unlocked_inode_to_wb_begin(inode, &locked);
 		if (TestClearPageDirty(page)) {
-			mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_DIRTY);
+			mem_cgroup_dec_page_stat(page, NR_FILE_DIRTY);
 			dec_node_page_state(page, NR_FILE_DIRTY);
 			dec_zone_page_state(page, NR_ZONE_WRITE_PENDING);
 			dec_wb_stat(wb, WB_RECLAIMABLE);
@@ -2753,7 +2753,7 @@ int test_clear_page_writeback(struct page *page)
 		ret = TestClearPageWriteback(page);
 	}
 	if (ret) {
-		mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_WRITEBACK);
+		mem_cgroup_dec_page_stat(page, NR_WRITEBACK);
 		dec_node_page_state(page, NR_WRITEBACK);
 		dec_zone_page_state(page, NR_ZONE_WRITE_PENDING);
 		inc_node_page_state(page, NR_WRITTEN);
@@ -2808,7 +2808,7 @@ int __test_set_page_writeback(struct page *page, bool keep_write)
 		ret = TestSetPageWriteback(page);
 	}
 	if (!ret) {
-		mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_WRITEBACK);
+		mem_cgroup_inc_page_stat(page, NR_WRITEBACK);
 		inc_node_page_state(page, NR_WRITEBACK);
 		inc_zone_page_state(page, NR_ZONE_WRITE_PENDING);
 	}
diff --git a/mm/rmap.c b/mm/rmap.c
index e303fdbee561..a6d018c4a13a 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1158,7 +1158,7 @@ void page_add_file_rmap(struct page *page, bool compound)
 			goto out;
 	}
 	__mod_node_page_state(page_pgdat(page), NR_FILE_MAPPED, nr);
-	mem_cgroup_update_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED, nr);
+	mem_cgroup_update_page_stat(page, NR_FILE_MAPPED, nr);
 out:
 	unlock_page_memcg(page);
 }
@@ -1198,7 +1198,7 @@ static void page_remove_file_rmap(struct page *page, bool compound)
 	 * pte lock(a spinlock) is held, which implies preemption disabled.
 	 */
 	__mod_node_page_state(page_pgdat(page), NR_FILE_MAPPED, -nr);
-	mem_cgroup_update_page_stat(page, MEM_CGROUP_STAT_FILE_MAPPED, -nr);
+	mem_cgroup_update_page_stat(page, NR_FILE_MAPPED, -nr);
 
 	if (unlikely(PageMlocked(page)))
 		clear_page_mlock(page);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index fbec74af2b69..417b6657e994 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2046,8 +2046,7 @@ static bool inactive_list_is_low(struct lruvec *lruvec, bool file,
 	active = lruvec_lru_size(lruvec, active_lru, sc->reclaim_idx);
 
 	if (memcg)
-		refaults = mem_cgroup_read_stat(memcg,
-						MEMCG_WORKINGSET_ACTIVATE);
+		refaults = mem_cgroup_read_stat(memcg, WORKINGSET_ACTIVATE);
 	else
 		refaults = node_page_state(pgdat, WORKINGSET_ACTIVATE);
 
@@ -2735,7 +2734,7 @@ static void snapshot_refaults(struct mem_cgroup *root_memcg, pg_data_t *pgdat)
 
 		if (memcg)
 			refaults = mem_cgroup_read_stat(memcg,
-						MEMCG_WORKINGSET_ACTIVATE);
+							WORKINGSET_ACTIVATE);
 		else
 			refaults = node_page_state(pgdat, WORKINGSET_ACTIVATE);
 
diff --git a/mm/workingset.c b/mm/workingset.c
index 51c6f61d4cea..37fc1057cd86 100644
--- a/mm/workingset.c
+++ b/mm/workingset.c
@@ -289,11 +289,11 @@ bool workingset_refault(void *shadow)
 	refault_distance = (refault - eviction) & EVICTION_MASK;
 
 	inc_node_state(pgdat, WORKINGSET_REFAULT);
-	mem_cgroup_inc_stat(memcg, MEMCG_WORKINGSET_REFAULT);
+	mem_cgroup_inc_stat(memcg, WORKINGSET_REFAULT);
 
 	if (refault_distance <= active_file) {
 		inc_node_state(pgdat, WORKINGSET_ACTIVATE);
-		mem_cgroup_inc_stat(memcg, MEMCG_WORKINGSET_ACTIVATE);
+		mem_cgroup_inc_stat(memcg, WORKINGSET_ACTIVATE);
 		rcu_read_unlock();
 		return true;
 	}
@@ -475,8 +475,7 @@ static enum lru_status shadow_lru_isolate(struct list_head *item,
 	if (WARN_ON_ONCE(node->exceptional))
 		goto out_invalid;
 	inc_node_state(page_pgdat(virt_to_page(node)), WORKINGSET_NODERECLAIM);
-	mem_cgroup_inc_page_stat(virt_to_page(node),
-				 MEMCG_WORKINGSET_NODERECLAIM);
+	mem_cgroup_inc_page_stat(virt_to_page(node), WORKINGSET_NODERECLAIM);
 	__radix_tree_delete_node(&mapping->page_tree, node,
 				 workingset_update_node, mapping);