[PATCH 1/4] mm: rearrange node_stat_item to put memcg stats at start

[Shakeel Butt <shakeel.butt@linux.dev>]

At the moment the memcg stats are sized based on the size of enum
node_stat_item but not all fields in node_stat_item corresponds to memcg
stats. So, rearrage the contents of node_stat_item such that all the
memcg specific stats are at the top and then the later patches will make
sure that the memcg code will not waste space for non-memcg stats.

Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
---
 include/linux/mmzone.h | 25 +++++++++++++------------
 mm/vmstat.c            | 24 ++++++++++++------------
 2 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 8f9c9590a42c..989ca97402c6 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -166,9 +166,6 @@ enum node_stat_item {
 	NR_UNEVICTABLE,		/*  "     "     "   "       "         */
 	NR_SLAB_RECLAIMABLE_B,
 	NR_SLAB_UNRECLAIMABLE_B,
-	NR_ISOLATED_ANON,	/* Temporary isolated pages from anon lru */
-	NR_ISOLATED_FILE,	/* Temporary isolated pages from file lru */
-	WORKINGSET_NODES,
 	WORKINGSET_REFAULT_BASE,
 	WORKINGSET_REFAULT_ANON = WORKINGSET_REFAULT_BASE,
 	WORKINGSET_REFAULT_FILE,
@@ -179,39 +176,43 @@ enum node_stat_item {
 	WORKINGSET_RESTORE_ANON = WORKINGSET_RESTORE_BASE,
 	WORKINGSET_RESTORE_FILE,
 	WORKINGSET_NODERECLAIM,
+	NR_PAGETABLE,		/* used for pagetables */
+	NR_SECONDARY_PAGETABLE, /* secondary pagetables, KVM & IOMMU */
+	NR_KERNEL_STACK_KB,	/* measured in KiB */
 	NR_ANON_MAPPED,	/* Mapped anonymous pages */
 	NR_FILE_MAPPED,	/* pagecache pages mapped into pagetables.
 			   only modified from process context */
 	NR_FILE_PAGES,
+#ifdef CONFIG_SWAP
+	NR_SWAPCACHE,
+#endif
 	NR_FILE_DIRTY,
 	NR_WRITEBACK,
-	NR_WRITEBACK_TEMP,	/* Writeback using temporary buffers */
 	NR_SHMEM,		/* shmem pages (included tmpfs/GEM pages) */
 	NR_SHMEM_THPS,
-	NR_SHMEM_PMDMAPPED,
 	NR_FILE_THPS,
-	NR_FILE_PMDMAPPED,
 	NR_ANON_THPS,
+	/* No memcg stats for the following fields. */
+	NR_SHMEM_PMDMAPPED,
+	NR_FILE_PMDMAPPED,
+	NR_WRITEBACK_TEMP,	/* Writeback using temporary buffers */
 	NR_VMSCAN_WRITE,
 	NR_VMSCAN_IMMEDIATE,	/* Prioritise for reclaim when writeback ends */
+	NR_ISOLATED_ANON,	/* Temporary isolated pages from anon lru */
+	NR_ISOLATED_FILE,	/* Temporary isolated pages from file lru */
+	WORKINGSET_NODES,
 	NR_DIRTIED,		/* page dirtyings since bootup */
 	NR_WRITTEN,		/* page writings since bootup */
 	NR_THROTTLED_WRITTEN,	/* NR_WRITTEN while reclaim throttled */
 	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_PAGETABLE,		/* used for pagetables */
-	NR_SECONDARY_PAGETABLE, /* secondary pagetables, KVM & IOMMU */
 #ifdef CONFIG_IOMMU_SUPPORT
 	NR_IOMMU_PAGES,		/* # of pages allocated by IOMMU */
 #endif
-#ifdef CONFIG_SWAP
-	NR_SWAPCACHE,
-#endif
 #ifdef CONFIG_NUMA_BALANCING
 	PGPROMOTE_SUCCESS,	/* promote successfully */
 	PGPROMOTE_CANDIDATE,	/* candidate pages to promote */
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 8507c497218b..4eac2f6322a3 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1206,9 +1206,6 @@ const char * const vmstat_text[] = {
 	"nr_unevictable",
 	"nr_slab_reclaimable",
 	"nr_slab_unreclaimable",
-	"nr_isolated_anon",
-	"nr_isolated_file",
-	"workingset_nodes",
 	"workingset_refault_anon",
 	"workingset_refault_file",
 	"workingset_activate_anon",
@@ -1216,38 +1213,41 @@ const char * const vmstat_text[] = {
 	"workingset_restore_anon",
 	"workingset_restore_file",
 	"workingset_nodereclaim",
+	"nr_page_table_pages",
+	"nr_sec_page_table_pages",
+	"nr_kernel_stack",
 	"nr_anon_pages",
 	"nr_mapped",
 	"nr_file_pages",
+#ifdef CONFIG_SWAP
+	"nr_swapcached",
+#endif
 	"nr_dirty",
 	"nr_writeback",
-	"nr_writeback_temp",
 	"nr_shmem",
 	"nr_shmem_hugepages",
-	"nr_shmem_pmdmapped",
 	"nr_file_hugepages",
-	"nr_file_pmdmapped",
 	"nr_anon_transparent_hugepages",
+	"nr_shmem_pmdmapped",
+	"nr_file_pmdmapped",
+	"nr_writeback_temp",
 	"nr_vmscan_write",
 	"nr_vmscan_immediate_reclaim",
+	"nr_isolated_anon",
+	"nr_isolated_file",
+	"workingset_nodes",
 	"nr_dirtied",
 	"nr_written",
 	"nr_throttled_written",
 	"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
-	"nr_page_table_pages",
-	"nr_sec_page_table_pages",
 #ifdef CONFIG_IOMMU_SUPPORT
 	"nr_iommu_pages",
 #endif
-#ifdef CONFIG_SWAP
-	"nr_swapcached",
-#endif
 #ifdef CONFIG_NUMA_BALANCING
 	"pgpromote_success",
 	"pgpromote_candidate",
-- 
2.43.0