[patch 1/2] mm: vmstat: introduce node_page_state_pages_snapshot

Marcelo Tosatti
2023-11-13T23:52:17Z

Introduce a _snapshot variant of node_page_state_snapshot,
similar to zone_page_state_snapshot.

To be used by next patch.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

---
include/linux/vmstat.h | 4 ++++
mm/vmstat.c | 28 ++++++++++++++++++++++++++++
2 files changed, 32 insertions(+)

Index: linux/mm/vmstat.c
===================================================================
--- linux.orig/mm/vmstat.c
+++ linux/mm/vmstat.c
@@ -1031,6 +1031,34 @@ unsigned long node_page_state(struct pgl

return node_page_state_pages(pgdat, item);
}
+
+/*
+ * Determine the per node value of a stat item, snapshot version
+ * (see comment on top zone_page_state_snapshot).
+ */
+unsigned long node_page_state_pages_snapshot(struct pglist_data *pgdat,
+ enum node_stat_item item)
+{
+ long x = atomic_long_read(&pgdat->vm_stat[item]);
+#ifdef CONFIG_SMP
+ int cpu;
+
+ for_each_online_cpu(cpu)
+ x += per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->vm_node_stat_diff[item];
+
+ if (x < 0)
+ x = 0;
+#endif
+ return x;
+}
+
+unsigned long node_page_state_snapshot(struct pglist_data *pgdat,
+ enum node_stat_item item)
+{
+ VM_WARN_ON_ONCE(vmstat_item_in_bytes(item));
+
+ return node_page_state_pages(pgdat, item);
+}
#endif

#ifdef CONFIG_COMPACTION
Index: linux/include/linux/vmstat.h
===================================================================
--- linux.orig/include/linux/vmstat.h
+++ linux/include/linux/vmstat.h
@@ -262,6 +262,10 @@ extern unsigned long node_page_state(str
enum node_stat_item item);
extern unsigned long node_page_state_pages(struct pglist_data *pgdat,
enum node_stat_item item);
+extern unsigned long node_page_state_snapshot(struct pglist_data *pgdat,
+ enum node_stat_item item);
+extern unsigned long node_page_state_pages_snapshot(struct pglist_data *pgdat,
+ enum node_stat_item item);
extern void fold_vm_numa_events(void);
#else
#define sum_zone_node_page_state(node, item) global_zone_page_state(item)