mm: add system wide stats items category

/proc/vmstat contains events and stats, events can only grow, but stats
can grow and shrink.

vmstat has the following:
-------------------------
NR_VM_ZONE_STAT_ITEMS:	per-zone stats
NR_VM_NUMA_EVENT_ITEMS:	per-numa events
NR_VM_NODE_STAT_ITEMS:	per-numa stats
NR_VM_WRITEBACK_STAT_ITEMS:	system-wide background-writeback and
				dirty-throttling tresholds.
NR_VM_EVENT_ITEMS:	system-wide events
-------------------------

Rename NR_VM_WRITEBACK_STAT_ITEMS to NR_VM_STAT_ITEMS, to track the
system-wide stats, we are going to add per-page metadata stats to this
category in the next patch.

Also delete unused writeback_stat_name().

Link: https://lkml.kernel.org/r/20240809191020.1142142-2-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20240808213437.682006-3-pasha.tatashin@soleen.com
Fixes: 15995a352474 ("mm: report per-page metadata information")
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Suggested-by: Yosry Ahmed <yosryahmed@google.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Joel Granados <j.granados@samsung.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yi Zhang <yi.zhang@redhat.com>
Cc: Fan Ni <fan.ni@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 23cd179..9ab4fa5 100644 (file)
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -34,10 +34,11 @@ struct reclaim_stat {
        unsigned nr_lazyfree_fail;
 };
 
-enum writeback_stat_item {
+/* Stat data for system wide items */
+enum vm_stat_item {
        NR_DIRTY_THRESHOLD,
        NR_DIRTY_BG_THRESHOLD,
-       NR_VM_WRITEBACK_STAT_ITEMS,
+       NR_VM_STAT_ITEMS,
 };
 
 #ifdef CONFIG_VM_EVENT_COUNTERS
@@ -514,21 +515,13 @@ static inline const char *lru_list_name(enum lru_list lru)
        return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
 }
 
-static inline const char *writeback_stat_name(enum writeback_stat_item item)
-{
-       return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
-                          NR_VM_NUMA_EVENT_ITEMS +
-                          NR_VM_NODE_STAT_ITEMS +
-                          item];
-}
-
 #if defined(CONFIG_VM_EVENT_COUNTERS) || defined(CONFIG_MEMCG)
 static inline const char *vm_event_name(enum vm_event_item item)
 {
        return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
                           NR_VM_NUMA_EVENT_ITEMS +
                           NR_VM_NODE_STAT_ITEMS +
-                          NR_VM_WRITEBACK_STAT_ITEMS +
+                          NR_VM_STAT_ITEMS +
                           item];
 }
 #endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */

diff --git a/mm/vmstat.c b/mm/vmstat.c
index 04a1cb6..6f8aa47 100644 (file)
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1257,7 +1257,7 @@ const char * const vmstat_text[] = {
        "pgdemote_khugepaged",
        "nr_memmap",
        "nr_memmap_boot",
-       /* enum writeback_stat_item counters */
+       /* system-wide enum vm_stat_item counters */
        "nr_dirty_threshold",
        "nr_dirty_background_threshold",
 
@@ -1790,7 +1790,7 @@ static const struct seq_operations zoneinfo_op = {
 #define NR_VMSTAT_ITEMS (NR_VM_ZONE_STAT_ITEMS + \
                         NR_VM_NUMA_EVENT_ITEMS + \
                         NR_VM_NODE_STAT_ITEMS + \
-                        NR_VM_WRITEBACK_STAT_ITEMS + \
+                        NR_VM_STAT_ITEMS + \
                         (IS_ENABLED(CONFIG_VM_EVENT_COUNTERS) ? \
                          NR_VM_EVENT_ITEMS : 0))
 
@@ -1827,7 +1827,7 @@ static void *vmstat_start(struct seq_file *m, loff_t *pos)
 
        global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
                            v + NR_DIRTY_THRESHOLD);
-       v += NR_VM_WRITEBACK_STAT_ITEMS;
+       v += NR_VM_STAT_ITEMS;
 
 #ifdef CONFIG_VM_EVENT_COUNTERS
        all_vm_events(v);