[PATCH v2] mm: memcontrol: account pagetables per node

[Shakeel Butt <shakeelb@google.com>]

For many workloads, pagetable consumption is significant and it makes
sense to expose it in the memory.stat for the memory cgroups. However at
the moment, the pagetables are accounted per-zone. Converting them to
per-node and using the right interface will correctly account for the
memory cgroups as well.

Signed-off-by: Shakeel Butt <shakeelb@google.com>
---
Changes since v1:
- Tried to fix linking errors for m68k and nds32


 Documentation/admin-guide/cgroup-v2.rst |  3 +++
 arch/m68k/include/asm/mcf_pgalloc.h     |  1 +
 arch/nds32/mm/mm-nds32.c                |  7 ++++---
 drivers/base/node.c                     |  2 +-
 fs/proc/meminfo.c                       |  2 +-
 include/linux/mm.h                      | 11 +++++++----
 include/linux/mmzone.h                  |  2 +-
 mm/memcontrol.c                         |  1 +
 mm/page_alloc.c                         |  6 +++---
 9 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 515bb13084a0..63521cd36ce5 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1274,6 +1274,9 @@ PAGE_SIZE multiple when read back.
 	  kernel_stack
 		Amount of memory allocated to kernel stacks.
 
+	  pagetables
+                Amount of memory allocated for page tables.
+
 	  percpu(npn)
 		Amount of memory used for storing per-cpu kernel
 		data structures.
diff --git a/arch/m68k/include/asm/mcf_pgalloc.h b/arch/m68k/include/asm/mcf_pgalloc.h
index bc1228e00518..9088812c2174 100644
--- a/arch/m68k/include/asm/mcf_pgalloc.h
+++ b/arch/m68k/include/asm/mcf_pgalloc.h
@@ -4,6 +4,7 @@
 
 #include <asm/tlb.h>
 #include <asm/tlbflush.h>
+#include <linux/memcontrol.h>
 
 extern inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
 {
diff --git a/arch/nds32/mm/mm-nds32.c b/arch/nds32/mm/mm-nds32.c
index 55bec50ccc03..d18e59877503 100644
--- a/arch/nds32/mm/mm-nds32.c
+++ b/arch/nds32/mm/mm-nds32.c
@@ -5,6 +5,7 @@
 
 #define __HAVE_ARCH_PGD_FREE
 #include <asm/pgalloc.h>
+#include <linux/memcontrol.h>
 
 #define FIRST_KERNEL_PGD_NR	(USER_PTRS_PER_PGD)
 
@@ -34,8 +35,8 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
 	cpu_dcache_wb_range((unsigned long)new_pgd,
 			    (unsigned long)new_pgd +
 			    PTRS_PER_PGD * sizeof(pgd_t));
-	inc_zone_page_state(virt_to_page((unsigned long *)new_pgd),
-			    NR_PAGETABLE);
+	inc_lruvec_page_state(virt_to_page((unsigned long *)new_pgd),
+			      NR_PAGETABLE);
 
 	return new_pgd;
 }
@@ -59,7 +60,7 @@ void pgd_free(struct mm_struct *mm, pgd_t * pgd)
 
 	pte = pmd_page(*pmd);
 	pmd_clear(pmd);
-	dec_zone_page_state(virt_to_page((unsigned long *)pgd), NR_PAGETABLE);
+	dec_lruvec_page_state(virt_to_page((unsigned long *)pgd), NR_PAGETABLE);
 	pte_free(mm, pte);
 	mm_dec_nr_ptes(mm);
 	pmd_free(mm, pmd);
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 6ffa470e2984..04f71c7bc3f8 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -450,7 +450,7 @@ static ssize_t node_read_meminfo(struct device *dev,
 #ifdef CONFIG_SHADOW_CALL_STACK
 			     nid, node_page_state(pgdat, NR_KERNEL_SCS_KB),
 #endif
-			     nid, K(sum_zone_node_page_state(nid, NR_PAGETABLE)),
+			     nid, K(node_page_state(pgdat, NR_PAGETABLE)),
 			     nid, 0UL,
 			     nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
 			     nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 887a5532e449..d6fc74619625 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -107,7 +107,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
 		   global_node_page_state(NR_KERNEL_SCS_KB));
 #endif
 	show_val_kb(m, "PageTables:     ",
-		    global_zone_page_state(NR_PAGETABLE));
+		    global_node_page_state(NR_PAGETABLE));
 
 	show_val_kb(m, "NFS_Unstable:   ", 0);
 	show_val_kb(m, "Bounce:         ",
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 7cfc4653dddf..15c8d082e32f 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2177,12 +2177,15 @@ static inline void pgtable_init(void)
 	pgtable_cache_init();
 }
 
+static void inc_lruvec_page_state(struct page *page, enum node_stat_item idx);
+static void dec_lruvec_page_state(struct page *page, enum node_stat_item idx);
+
 static inline bool pgtable_pte_page_ctor(struct page *page)
 {
 	if (!ptlock_init(page))
 		return false;
 	__SetPageTable(page);
-	inc_zone_page_state(page, NR_PAGETABLE);
+	inc_lruvec_page_state(page, NR_PAGETABLE);
 	return true;
 }
 
@@ -2190,7 +2193,7 @@ static inline void pgtable_pte_page_dtor(struct page *page)
 {
 	ptlock_free(page);
 	__ClearPageTable(page);
-	dec_zone_page_state(page, NR_PAGETABLE);
+	dec_lruvec_page_state(page, NR_PAGETABLE);
 }
 
 #define pte_offset_map_lock(mm, pmd, address, ptlp)	\
@@ -2277,7 +2280,7 @@ static inline bool pgtable_pmd_page_ctor(struct page *page)
 	if (!pmd_ptlock_init(page))
 		return false;
 	__SetPageTable(page);
-	inc_zone_page_state(page, NR_PAGETABLE);
+	inc_lruvec_page_state(page, NR_PAGETABLE);
 	return true;
 }
 
@@ -2285,7 +2288,7 @@ static inline void pgtable_pmd_page_dtor(struct page *page)
 {
 	pmd_ptlock_free(page);
 	__ClearPageTable(page);
-	dec_zone_page_state(page, NR_PAGETABLE);
+	dec_lruvec_page_state(page, NR_PAGETABLE);
 }
 
 /*
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 8b074e2ba12c..0dead297d1f1 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -151,7 +151,6 @@ enum zone_stat_item {
 	NR_ZONE_UNEVICTABLE,
 	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 */
 	/* Second 128 byte cacheline */
 	NR_BOUNCE,
 #if IS_ENABLED(CONFIG_ZSMALLOC)
@@ -206,6 +205,7 @@ enum node_stat_item {
 #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK)
 	NR_KERNEL_SCS_KB,	/* measured in KiB */
 #endif
+	NR_PAGETABLE,		/* used for pagetables */
 	NR_VM_NODE_STAT_ITEMS
 };
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 45465c03a8d7..29a558279520 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1501,6 +1501,7 @@ static struct memory_stat memory_stats[] = {
 	{ "anon", PAGE_SIZE, NR_ANON_MAPPED },
 	{ "file", PAGE_SIZE, NR_FILE_PAGES },
 	{ "kernel_stack", 1024, NR_KERNEL_STACK_KB },
+	{ "pagetables", PAGE_SIZE, NR_PAGETABLE },
 	{ "percpu", 1, MEMCG_PERCPU_B },
 	{ "sock", PAGE_SIZE, MEMCG_SOCK },
 	{ "shmem", PAGE_SIZE, NR_SHMEM },
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 42c32e8a9c5d..074664f1ea23 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5515,7 +5515,7 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
 		global_node_page_state_pages(NR_SLAB_UNRECLAIMABLE_B),
 		global_node_page_state(NR_FILE_MAPPED),
 		global_node_page_state(NR_SHMEM),
-		global_zone_page_state(NR_PAGETABLE),
+		global_node_page_state(NR_PAGETABLE),
 		global_zone_page_state(NR_BOUNCE),
 		global_zone_page_state(NR_FREE_PAGES),
 		free_pcp,
@@ -5547,6 +5547,7 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
 #ifdef CONFIG_SHADOW_CALL_STACK
 			" shadow_call_stack:%lukB"
 #endif
+			" pagetables:%lukB"
 			" all_unreclaimable? %s"
 			"\n",
 			pgdat->node_id,
@@ -5572,6 +5573,7 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
 #ifdef CONFIG_SHADOW_CALL_STACK
 			node_page_state(pgdat, NR_KERNEL_SCS_KB),
 #endif
+			K(node_page_state(pgdat, NR_PAGETABLE)),
 			pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES ?
 				"yes" : "no");
 	}
@@ -5603,7 +5605,6 @@ void show_free_areas(unsigned int filter, nodemask_t *nodemask)
 			" present:%lukB"
 			" managed:%lukB"
 			" mlocked:%lukB"
-			" pagetables:%lukB"
 			" bounce:%lukB"
 			" free_pcp:%lukB"
 			" local_pcp:%ukB"
@@ -5624,7 +5625,6 @@ 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)),
-			K(zone_page_state(zone, NR_PAGETABLE)),
 			K(zone_page_state(zone, NR_BOUNCE)),
 			K(free_pcp),
 			K(this_cpu_read(zone->pageset->pcp.count)),
-- 
2.29.2.454.gaff20da3a2-goog