mm: memcontrol: account kernel stack per node

Currently the kernel stack is being accounted per-zone.  There is no need
to do that.  In addition due to being per-zone, memcg has to keep a
separate MEMCG_KERNEL_STACK_KB.  Make the stat per-node and deprecate
MEMCG_KERNEL_STACK_KB as memcg_stat_item is an extension of
node_stat_item.  In addition localize the kernel stack stats updates to
account_kernel_stack().

Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Link: http://lkml.kernel.org/r/20200630161539.1759185-1-shakeelb@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/base/node.c

@@ -440,9 +440,9 @@ static ssize_t node_read_meminfo(struct device *dev,
 		       nid, K(node_page_state(pgdat, NR_FILE_MAPPED)),
 		       nid, K(node_page_state(pgdat, NR_ANON_MAPPED)),
 		       nid, K(i.sharedram),
-		       nid, sum_zone_node_page_state(nid, NR_KERNEL_STACK_KB),
+		       nid, node_page_state(pgdat, NR_KERNEL_STACK_KB),
 #ifdef CONFIG_SHADOW_CALL_STACK
-		       nid, sum_zone_node_page_state(nid, NR_KERNEL_SCS_KB),
+		       nid, node_page_state(pgdat, NR_KERNEL_SCS_KB),
 #endif
 		       nid, K(sum_zone_node_page_state(nid, NR_PAGETABLE)),
 		       nid, 0UL,

fs/proc/meminfo.c

@@ -101,10 +101,10 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
 	show_val_kb(m, "SReclaimable:   ", sreclaimable);
 	show_val_kb(m, "SUnreclaim:     ", sunreclaim);
 	seq_printf(m, "KernelStack:    %8lu kB\n",
-		   global_zone_page_state(NR_KERNEL_STACK_KB));
+		   global_node_page_state(NR_KERNEL_STACK_KB));
 #ifdef CONFIG_SHADOW_CALL_STACK
 	seq_printf(m, "ShadowCallStack:%8lu kB\n",
-		   global_zone_page_state(NR_KERNEL_SCS_KB));
+		   global_node_page_state(NR_KERNEL_SCS_KB));
 #endif
 	show_val_kb(m, "PageTables:     ",
 		    global_zone_page_state(NR_PAGETABLE));

include/linux/memcontrol.h

@@ -32,8 +32,6 @@ struct kmem_cache;
 enum memcg_stat_item {
 	MEMCG_SWAP = NR_VM_NODE_STAT_ITEMS,
 	MEMCG_SOCK,
-	/* XXX: why are these zone and not node counters? */
-	MEMCG_KERNEL_STACK_KB,
 	MEMCG_NR_STAT,
 };
 
@@ -729,8 +727,19 @@ void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
 void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
 			int val);
 void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val);
+
 void mod_memcg_obj_state(void *p, int idx, int val);
 
+static inline void mod_lruvec_slab_state(void *p, enum node_stat_item idx,
+					 int val)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__mod_lruvec_slab_state(p, idx, val);
+	local_irq_restore(flags);
+}
+
 static inline void mod_memcg_lruvec_state(struct lruvec *lruvec,
 					  enum node_stat_item idx, int val)
 {
@@ -1151,6 +1160,14 @@ static inline void __mod_lruvec_slab_state(void *p, enum node_stat_item idx,
 	__mod_node_page_state(page_pgdat(page), idx, val);
 }
 
+static inline void mod_lruvec_slab_state(void *p, enum node_stat_item idx,
+					 int val)
+{
+	struct page *page = virt_to_head_page(p);
+
+	mod_node_page_state(page_pgdat(page), idx, val);
+}
+
 static inline void mod_memcg_obj_state(void *p, int idx, int val)
 {
 }

include/linux/mmzone.h

@@ -155,10 +155,6 @@ enum zone_stat_item {
 	NR_ZONE_WRITE_PENDING,	/* Count of dirty, writeback and unstable pages */
 	NR_MLOCK,		/* mlock()ed pages found and moved off LRU */
 	NR_PAGETABLE,		/* used for pagetables */
-	NR_KERNEL_STACK_KB,	/* measured in KiB */
-#if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
-	NR_KERNEL_SCS_KB,	/* measured in KiB */
-#endif
 	/* Second 128 byte cacheline */
 	NR_BOUNCE,
 #if IS_ENABLED(CONFIG_ZSMALLOC)
@@ -203,6 +199,10 @@ enum node_stat_item {
 	NR_KERNEL_MISC_RECLAIMABLE,	/* reclaimable non-slab kernel pages */
 	NR_FOLL_PIN_ACQUIRED,	/* via: pin_user_page(), gup flag: FOLL_PIN */
 	NR_FOLL_PIN_RELEASED,	/* pages returned via unpin_user_page() */
+	NR_KERNEL_STACK_KB,	/* measured in KiB */
+#if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
+	NR_KERNEL_SCS_KB,	/* measured in KiB */
+#endif
 	NR_VM_NODE_STAT_ITEMS
 };
 

kernel/fork.c

@@ -276,13 +276,8 @@ static inline void free_thread_stack(struct task_struct *tsk)
 	if (vm) {
 		int i;
 
-		for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) {
-			mod_memcg_page_state(vm->pages[i],
-					     MEMCG_KERNEL_STACK_KB,
-					     -(int)(PAGE_SIZE / 1024));
-
+		for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++)
 			memcg_kmem_uncharge_page(vm->pages[i], 0);
-		}
 
 		for (i = 0; i < NR_CACHED_STACKS; i++) {
 			if (this_cpu_cmpxchg(cached_stacks[i],
@@ -382,31 +377,14 @@ static void account_kernel_stack(struct task_struct *tsk, int account)
 	void *stack = task_stack_page(tsk);
 	struct vm_struct *vm = task_stack_vm_area(tsk);
 
-	BUILD_BUG_ON(IS_ENABLED(CONFIG_VMAP_STACK) && PAGE_SIZE % 1024 != 0);
-
-	if (vm) {
-		int i;
-
-		BUG_ON(vm->nr_pages != THREAD_SIZE / PAGE_SIZE);
 
-		for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) {
-			mod_zone_page_state(page_zone(vm->pages[i]),
-					    NR_KERNEL_STACK_KB,
-					    PAGE_SIZE / 1024 * account);
-		}
-	} else {
-		/*
-		 * All stack pages are in the same zone and belong to the
-		 * same memcg.
-		 */
-		struct page *first_page = virt_to_page(stack);
-
-		mod_zone_page_state(page_zone(first_page), NR_KERNEL_STACK_KB,
-				    THREAD_SIZE / 1024 * account);
-
-		mod_memcg_obj_state(stack, MEMCG_KERNEL_STACK_KB,
-				    account * (THREAD_SIZE / 1024));
-	}
+	/* All stack pages are in the same node. */
+	if (vm)
+		mod_lruvec_page_state(vm->pages[0], NR_KERNEL_STACK_KB,
+				      account * (THREAD_SIZE / 1024));
+	else
+		mod_lruvec_slab_state(stack, NR_KERNEL_STACK_KB,
+				      account * (THREAD_SIZE / 1024));
 }
 
 static int memcg_charge_kernel_stack(struct task_struct *tsk)
@@ -415,24 +393,23 @@ static int memcg_charge_kernel_stack(struct task_struct *tsk)
 	struct vm_struct *vm = task_stack_vm_area(tsk);
 	int ret;
 
+	BUILD_BUG_ON(IS_ENABLED(CONFIG_VMAP_STACK) && PAGE_SIZE % 1024 != 0);
+
 	if (vm) {
 		int i;
 
+		BUG_ON(vm->nr_pages != THREAD_SIZE / PAGE_SIZE);
+
 		for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) {
 			/*
 			 * If memcg_kmem_charge_page() fails, page->mem_cgroup
-			 * pointer is NULL, and both memcg_kmem_uncharge_page()
-			 * and mod_memcg_page_state() in free_thread_stack()
-			 * will ignore this page. So it's safe.
+			 * pointer is NULL, and memcg_kmem_uncharge_page() in
+			 * free_thread_stack() will ignore this page.
 			 */
 			ret = memcg_kmem_charge_page(vm->pages[i], GFP_KERNEL,
 						     0);
 			if (ret)
 				return ret;
-
-			mod_memcg_page_state(vm->pages[i],
-					     MEMCG_KERNEL_STACK_KB,
-					     PAGE_SIZE / 1024);
 		}
 	}
 #endif

kernel/scs.c

@@ -17,7 +17,7 @@ static void __scs_account(void *s, int account)
 {
 	struct page *scs_page = virt_to_page(s);
 
-	mod_zone_page_state(page_zone(scs_page), NR_KERNEL_SCS_KB,
+	mod_node_page_state(page_pgdat(scs_page), NR_KERNEL_SCS_KB,
 			    account * (SCS_SIZE / SZ_1K));
 }
 

mm/memcontrol.c

@@ -1485,7 +1485,7 @@ static char *memory_stat_format(struct mem_cgroup *memcg)
 		       (u64)memcg_page_state(memcg, NR_FILE_PAGES) *
 		       PAGE_SIZE);
 	seq_buf_printf(&s, "kernel_stack %llu\n",
-		       (u64)memcg_page_state(memcg, MEMCG_KERNEL_STACK_KB) *
+		       (u64)memcg_page_state(memcg, NR_KERNEL_STACK_KB) *
 		       1024);
 	seq_buf_printf(&s, "slab %llu\n",
 		       (u64)(memcg_page_state(memcg, NR_SLAB_RECLAIMABLE_B) +

mm/page_alloc.c

@@ -5396,6 +5396,10 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
 			" anon_thp: %lukB"
 #endif
 			" writeback_tmp:%lukB"
+			" kernel_stack:%lukB"
+#ifdef CONFIG_SHADOW_CALL_STACK
+			" shadow_call_stack:%lukB"
+#endif
 			" all_unreclaimable? %s"
 			"\n",
 			pgdat->node_id,
@@ -5417,6 +5421,10 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
 			K(node_page_state(pgdat, NR_ANON_THPS) * HPAGE_PMD_NR),
 #endif
 			K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
+			node_page_state(pgdat, NR_KERNEL_STACK_KB),
+#ifdef CONFIG_SHADOW_CALL_STACK
+			node_page_state(pgdat, NR_KERNEL_SCS_KB),
+#endif
 			pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ?
 				"yes" : "no");
 	}
@@ -5448,10 +5456,6 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
 			" present:%lukB"
 			" managed:%lukB"
 			" mlocked:%lukB"
-			" kernel_stack:%lukB"
-#ifdef CONFIG_SHADOW_CALL_STACK
-			" shadow_call_stack:%lukB"
-#endif
 			" pagetables:%lukB"
 			" bounce:%lukB"
 			" free_pcp:%lukB"
@@ -5473,10 +5477,6 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
 			K(zone->present_pages),
 			K(zone_managed_pages(zone)),
 			K(zone_page_state(zone, NR_MLOCK)),
-			zone_page_state(zone, NR_KERNEL_STACK_KB),
-#ifdef CONFIG_SHADOW_CALL_STACK
-			zone_page_state(zone, NR_KERNEL_SCS_KB),
-#endif
 			K(zone_page_state(zone, NR_PAGETABLE)),
 			K(zone_page_state(zone, NR_BOUNCE)),
 			K(free_pcp),

mm/vmstat.c

@@ -1140,10 +1140,6 @@ const char * const vmstat_text[] = {
 	"nr_zone_write_pending",
 	"nr_mlock",
 	"nr_page_table_pages",
-	"nr_kernel_stack",
-#if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
-	"nr_shadow_call_stack",
-#endif
 	"nr_bounce",
 #if IS_ENABLED(CONFIG_ZSMALLOC)
 	"nr_zspages",
@@ -1194,6 +1190,10 @@ const char * const vmstat_text[] = {
 	"nr_kernel_misc_reclaimable",
 	"nr_foll_pin_acquired",
 	"nr_foll_pin_released",
+	"nr_kernel_stack",
+#if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
+	"nr_shadow_call_stack",
+#endif
 
 	/* enum writeback_stat_item counters */
 	"nr_dirty_threshold",