Add a new CONFIG_PER_VMA_LOCK_STATS config option to dump extra
statistics about handling page fault under VMA lock.
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
---
include/linux/vm_event_item.h | 6 ++++++
include/linux/vmstat.h | 6 ++++++
mm/Kconfig.debug | 6 ++++++
mm/memory.c | 2 ++
mm/vmstat.c | 6 ++++++
5 files changed, 26 insertions(+)
diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index 7f5d1caf5890..8abfa1240040 100644
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -149,6 +149,12 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
#ifdef CONFIG_X86
DIRECT_MAP_LEVEL2_SPLIT,
DIRECT_MAP_LEVEL3_SPLIT,
+#endif
+#ifdef CONFIG_PER_VMA_LOCK_STATS
+ VMA_LOCK_SUCCESS,
+ VMA_LOCK_ABORT,
+ VMA_LOCK_RETRY,
+ VMA_LOCK_MISS,
#endif
NR_VM_EVENT_ITEMS
};
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 19cf5b6892ce..fed855bae6d8 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -125,6 +125,12 @@ static inline void vm_events_fold_cpu(int cpu)
#define count_vm_tlb_events(x, y) do { (void)(y); } while (0)
#endif
+#ifdef CONFIG_PER_VMA_LOCK_STATS
+#define count_vm_vma_lock_event(x) count_vm_event(x)
+#else
+#define count_vm_vma_lock_event(x) do {} while (0)
+#endif
+
#define __count_zid_vm_events(item, zid, delta) \
__count_vm_events(item##_NORMAL - ZONE_NORMAL + zid, delta)
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
index c3547a373c9c..4965a7333a3f 100644
--- a/mm/Kconfig.debug
+++ b/mm/Kconfig.debug
@@ -279,3 +279,9 @@ config DEBUG_KMEMLEAK_AUTO_SCAN
If unsure, say Y.
+config PER_VMA_LOCK_STATS
+ bool "Statistics for per-vma locks"
+ depends on PER_VMA_LOCK
+ default y
+ help
+ Statistics for per-vma locks.
diff --git a/mm/memory.c b/mm/memory.c
index 751aebc1b29f..94194a45ffa7 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5272,6 +5272,7 @@ struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm,
/* Check if the VMA got isolated after we found it */
if (vma->detached) {
vma_end_read(vma);
+ count_vm_vma_lock_event(VMA_LOCK_MISS);
/* The area was replaced with another one */
goto retry;
}
@@ -5280,6 +5281,7 @@ struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm,
return vma;
inval:
rcu_read_unlock();
+ count_vm_vma_lock_event(VMA_LOCK_ABORT);
return NULL;
}
#endif /* CONFIG_PER_VMA_LOCK */
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 1ea6a5ce1c41..4f1089a1860e 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1399,6 +1399,12 @@ const char * const vmstat_text[] = {
"direct_map_level2_splits",
"direct_map_level3_splits",
#endif
+#ifdef CONFIG_PER_VMA_LOCK_STATS
+ "vma_lock_success",
+ "vma_lock_abort",
+ "vma_lock_retry",
+ "vma_lock_miss",
+#endif
#endif /* CONFIG_VM_EVENT_COUNTERS || CONFIG_MEMCG */
};
#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_MEMCG */
--
2.39.1
