Add a perf context level that doesn't measure time for mutex operations

Summary: Timing mutex operations can impact scalability of the system. Add a new perf context level that can measure time counters except for mutex.

Test Plan: Add a new unit test case to make sure it is not set.

Reviewers: IslamAbdelRahman, rven, kradhakrishnan, yhchiang, anthony

Reviewed By: anthony

Subscribers: MarkCallaghan, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D53199

3 files changed, 16 insertions, 16 deletions

diff --git a/util/instrumented_mutex.cc b/util/instrumented_mutex.cc
index bfb989a1d..e5c6527be 100644
--- a/util/instrumented_mutex.cc
+++ b/util/instrumented_mutex.cc
@@ -9,8 +9,8 @@
 
 namespace rocksdb {
 void InstrumentedMutex::Lock() {
-  PERF_CONDITIONAL_TIMER_GUARD(db_mutex_lock_nanos,
-                               stats_code_ == DB_MUTEX_WAIT_MICROS);
+  PERF_CONDITIONAL_TIMER_FOR_MUTEX_GUARD(db_mutex_lock_nanos,
+                                         stats_code_ == DB_MUTEX_WAIT_MICROS);
   uint64_t wait_time_micros = 0;
   if (env_ != nullptr && stats_ != nullptr) {
     {
@@ -31,8 +31,8 @@ void InstrumentedMutex::LockInternal() {
 }
 
 void InstrumentedCondVar::Wait() {
-  PERF_CONDITIONAL_TIMER_GUARD(db_condition_wait_nanos,
-                               stats_code_ == DB_MUTEX_WAIT_MICROS);
+  PERF_CONDITIONAL_TIMER_FOR_MUTEX_GUARD(db_condition_wait_nanos,
+                                         stats_code_ == DB_MUTEX_WAIT_MICROS);
   uint64_t wait_time_micros = 0;
   if (env_ != nullptr && stats_ != nullptr) {
     {
@@ -53,8 +53,8 @@ void InstrumentedCondVar::WaitInternal() {
 }
 
 bool InstrumentedCondVar::TimedWait(uint64_t abs_time_us) {
-  PERF_CONDITIONAL_TIMER_GUARD(db_condition_wait_nanos,
-                               stats_code_ == DB_MUTEX_WAIT_MICROS);
+  PERF_CONDITIONAL_TIMER_FOR_MUTEX_GUARD(db_condition_wait_nanos,
+                                         stats_code_ == DB_MUTEX_WAIT_MICROS);
   uint64_t wait_time_micros = 0;
   bool result = false;
   if (env_ != nullptr && stats_ != nullptr) {
diff --git a/util/perf_context_imp.h b/util/perf_context_imp.h
index a5c4c39d9..d28b55179 100644
--- a/util/perf_context_imp.h
+++ b/util/perf_context_imp.h
@@ -33,10 +33,10 @@ namespace rocksdb {
   PerfStepTimer perf_step_timer_ ## metric(&(perf_context.metric));   \
   perf_step_timer_ ## metric.Start();
 
-#define PERF_CONDITIONAL_TIMER_GUARD(metric, condition)           \
-  PerfStepTimer perf_step_timer_##metric(&(perf_context.metric)); \
-  if ((condition)) {                                              \
-    perf_step_timer_##metric.Start();                             \
+#define PERF_CONDITIONAL_TIMER_FOR_MUTEX_GUARD(metric, condition)       \
+  PerfStepTimer perf_step_timer_##metric(&(perf_context.metric), true); \
+  if ((condition)) {                                                    \
+    perf_step_timer_##metric.Start();                                   \
   }
 
 // Update metric with time elapsed since last START. start time is reset
diff --git a/util/perf_step_timer.h b/util/perf_step_timer.h
index 950258345..631cd317c 100644
--- a/util/perf_step_timer.h
+++ b/util/perf_step_timer.h
@@ -12,12 +12,12 @@ namespace rocksdb {
 
 class PerfStepTimer {
  public:
-  PerfStepTimer(uint64_t* metric)
-    : enabled_(perf_level >= PerfLevel::kEnableTime),
-      env_(enabled_ ? Env::Default() : nullptr),
-      start_(0),
-      metric_(metric) {
-  }
+  explicit PerfStepTimer(uint64_t* metric, bool for_mutex = false)
+      : enabled_(perf_level >= PerfLevel::kEnableTime ||
+                 (!for_mutex && perf_level >= kEnableTimeExceptForMutex)),
+        env_(enabled_ ? Env::Default() : nullptr),
+        start_(0),
+        metric_(metric) {}
 
   ~PerfStepTimer() {
     Stop();