diff mbox series

[v10,1/6] mm/vmstat: Add CPU-specific variable to track a vmstat discrepancy

Message ID 20221216194904.075275493@redhat.com (mailing list archive)
State New
Headers show
Series Ensure quiet_vmstat() is called when returning to userpace and when idle tick is stopped | expand

Commit Message

Marcelo Tosatti Dec. 16, 2022, 7:45 p.m. UTC 
From: Aaron Tomlin <atomlin@redhat.com>

Introduce a CPU-specific variable namely vmstat_dirty to indicate
if a vmstat imbalance is present for a given CPU. Therefore, at
the appropriate time, we can fold all the remaining differentials.
This patch also provides trivial helpers for modification and testing.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---
 mm/vmstat.c |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)
diff mbox series

Patch

Index: linux-2.6/mm/vmstat.c
===================================================================
--- linux-2.6.orig/mm/vmstat.c
+++ linux-2.6/mm/vmstat.c
@@ -194,6 +194,22 @@  void fold_vm_numa_events(void)
 #endif
 
 #ifdef CONFIG_SMP
+static DEFINE_PER_CPU_ALIGNED(bool, vmstat_dirty);
+
+static inline void vmstat_mark_dirty(void)
+{
+	this_cpu_write(vmstat_dirty, true);
+}
+
+static inline void vmstat_clear_dirty(void)
+{
+	this_cpu_write(vmstat_dirty, false);
+}
+
+static inline bool is_vmstat_dirty(void)
+{
+	return this_cpu_read(vmstat_dirty);
+}
 
 int calculate_pressure_threshold(struct zone *zone)
 {