mm: introduce per-VMA lock statistics

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@google.com>

diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index 3518dba1e02f4bdf5f6217a9ea8af2fad38f13af..2394461549a5ae8dd0a58141f149f53982ea0cef 100644 (file)
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -146,6 +146,12 @@ 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 19cf5b6892ceba12c9f8acfa0a7910b4a2e726d4..fed855bae6d8e88956064f85f1260bca522bb5fb 100644 (file)
--- 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 ce8dded36de94247fe2de6c3c2e83a097c851d5c..23cb08363572ef7d552c176d2c15b74b34711df1 100644 (file)
--- a/mm/Kconfig.debug
+++ b/mm/Kconfig.debug
@@ -207,3 +207,11 @@ config PTDUMP_DEBUGFS
          kernel.
 
          If in doubt, say N.
+
+
+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/vmstat.c b/mm/vmstat.c
index b2371d745e007f0ac5812c9727ffe636c66cb8c2..d232f546902f28062ad80f8f4212449c00902072 100644 (file)
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1396,6 +1396,12 @@ 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 */