[PATCH 19/27] mm: Move vmscan writes and file write accounting to the node

[Mel Gorman]

As reclaim is now node-based, it follows that page write activity
due to page reclaim should also be accounted for on the node. For
consistency, also account page writes and page dirtying on a per-node
basis.

After this patch, there are a few remaining zone counters that may
appear strange but are fine. NUMA stats are still per-zone as this is a
user-space interface that tools consume. NR_MLOCK, NR_SLAB_*, NR_PAGETABLE,
NR_KERNEL_STACK and NR_BOUNCE are all allocations that potentially pin
low memory and cannot trivially be reclaimed on demand. This information
is still useful for debugging a page allocation failure warning.

Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
---
 include/linux/mmzone.h           | 8 ++++----
 include/trace/events/writeback.h | 4 ++--
 mm/page-writeback.c              | 6 +++---
 mm/vmscan.c                      | 4 ++--
 mm/vmstat.c                      | 8 ++++----
 5 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 9924b46e3a13..9c59b8540cb7 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -121,10 +121,6 @@ enum zone_stat_item {
 	NR_KERNEL_STACK,
 	/* Second 128 byte cacheline */
 	NR_BOUNCE,
-	NR_VMSCAN_WRITE,
-	NR_VMSCAN_IMMEDIATE,	/* Prioritise for reclaim when writeback ends */
-	NR_DIRTIED,		/* page dirtyings since bootup */
-	NR_WRITTEN,		/* page writings since bootup */
 #if IS_ENABLED(CONFIG_ZSMALLOC)
 	NR_ZSPAGES,		/* allocated in zsmalloc */
 #endif
@@ -162,6 +158,10 @@ enum node_stat_item {
 	NR_WRITEBACK_TEMP,	/* Writeback using temporary buffers */
 	NR_SHMEM,		/* shmem pages (included tmpfs/GEM pages) */
 	NR_UNSTABLE_NFS,	/* NFS unstable pages */
+	NR_VMSCAN_WRITE,
+	NR_VMSCAN_IMMEDIATE,	/* Prioritise for reclaim when writeback ends */
+	NR_DIRTIED,		/* page dirtyings since bootup */
+	NR_WRITTEN,		/* page writings since bootup */
 	NR_VM_NODE_STAT_ITEMS
 };
 
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index c581d9c04ca5..a1002cfede1d 100644
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -415,8 +415,8 @@ TRACE_EVENT(global_dirty_state,
 		__entry->nr_dirty	= global_node_page_state(NR_FILE_DIRTY);
 		__entry->nr_writeback	= global_node_page_state(NR_WRITEBACK);
 		__entry->nr_unstable	= global_node_page_state(NR_UNSTABLE_NFS);
-		__entry->nr_dirtied	= global_page_state(NR_DIRTIED);
-		__entry->nr_written	= global_page_state(NR_WRITTEN);
+		__entry->nr_dirtied	= global_node_page_state(NR_DIRTIED);
+		__entry->nr_written	= global_node_page_state(NR_WRITTEN);
 		__entry->background_thresh = background_thresh;
 		__entry->dirty_thresh	= dirty_thresh;
 		__entry->dirty_limit	= global_wb_domain.dirty_limit;
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index aa9fa1eb8b80..95f38a59f9a0 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2433,7 +2433,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping)
 
 		mem_cgroup_inc_page_stat(page, MEM_CGROUP_STAT_DIRTY);
 		__inc_node_page_state(page, NR_FILE_DIRTY);
-		__inc_zone_page_state(page, NR_DIRTIED);
+		__inc_node_page_state(page, NR_DIRTIED);
 		__inc_wb_stat(wb, WB_RECLAIMABLE);
 		__inc_wb_stat(wb, WB_DIRTIED);
 		task_io_account_write(PAGE_SIZE);
@@ -2521,7 +2521,7 @@ void account_page_redirty(struct page *page)
 
 		wb = unlocked_inode_to_wb_begin(inode, &locked);
 		current->nr_dirtied--;
-		dec_zone_page_state(page, NR_DIRTIED);
+		dec_node_page_state(page, NR_DIRTIED);
 		dec_wb_stat(wb, WB_DIRTIED);
 		unlocked_inode_to_wb_end(inode, locked);
 	}
@@ -2750,7 +2750,7 @@ int test_clear_page_writeback(struct page *page)
 	if (ret) {
 		mem_cgroup_dec_page_stat(page, MEM_CGROUP_STAT_WRITEBACK);
 		dec_node_page_state(page, NR_WRITEBACK);
-		inc_zone_page_state(page, NR_WRITTEN);
+		inc_node_page_state(page, NR_WRITTEN);
 	}
 	unlock_page_memcg(page);
 	return ret;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 4501a9ab1d3f..1f7c1262c0a3 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -612,7 +612,7 @@ static pageout_t pageout(struct page *page, struct address_space *mapping,
 			ClearPageReclaim(page);
 		}
 		trace_mm_vmscan_writepage(page);
-		inc_zone_page_state(page, NR_VMSCAN_WRITE);
+		inc_node_page_state(page, NR_VMSCAN_WRITE);
 		return PAGE_SUCCESS;
 	}
 
@@ -1111,7 +1111,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 				 * except we already have the page isolated
 				 * and know it's dirty
 				 */
-				inc_zone_page_state(page, NR_VMSCAN_IMMEDIATE);
+				inc_node_page_state(page, NR_VMSCAN_IMMEDIATE);
 				SetPageReclaim(page);
 
 				goto keep_locked;
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 32c499251174..b58ceb8c872c 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -929,10 +929,6 @@ const char * const vmstat_text[] = {
 	"nr_page_table_pages",
 	"nr_kernel_stack",
 	"nr_bounce",
-	"nr_vmscan_write",
-	"nr_vmscan_immediate_reclaim",
-	"nr_dirtied",
-	"nr_written",
 #if IS_ENABLED(CONFIG_ZSMALLOC)
 	"nr_zspages",
 #endif
@@ -967,6 +963,10 @@ const char * const vmstat_text[] = {
 	"nr_writeback_temp",
 	"nr_shmem",
 	"nr_unstable",
+	"nr_vmscan_write",
+	"nr_vmscan_immediate_reclaim",
+	"nr_dirtied",
+	"nr_written",
 
 	/* enum writeback_stat_item counters */
 	"nr_dirty_threshold",
-- 
2.6.4