Roll back huge region demand-based release experiment.

PiperOrigin-RevId: 689025658
Change-Id: I0401a2def84751341655096ee484f19f6db290a7

tcmalloc/experiment_config.h

@@ -27,7 +27,6 @@ enum class Experiment : int {
   TEST_ONLY_TCMALLOC_HUGE_CACHE_RELEASE_30S,  // TODO(b/319872040): Complete experiment.
   TEST_ONLY_TCMALLOC_REUSE_SIZE_CLASSES,  // TODO(b/358126781): Complete experiment.
   TCMALLOC_REUSE_SIZE_CLASSES,  // TODO(b/358126781): Complete experiment.
-  TCMALLOC_HUGE_REGION_DEMAND_BASED_RELEASE,  // TODO(b/328440160): Complete experiment.
   TEST_ONLY_TCMALLOC_BIG_SPAN,  // TODO(b/304135905): Complete experiment.
   TCMALLOC_BIG_SPAN,  // TODO(b/304135905): Complete experiment.
   TEST_ONLY_L3_AWARE,  // TODO(b/239977380): Complete experiment.
@@ -49,7 +48,6 @@ inline constexpr ExperimentConfig experiments[] = {
     {Experiment::TEST_ONLY_TCMALLOC_HUGE_CACHE_RELEASE_30S, "TEST_ONLY_TCMALLOC_HUGE_CACHE_RELEASE_30S"},
     {Experiment::TEST_ONLY_TCMALLOC_REUSE_SIZE_CLASSES, "TEST_ONLY_TCMALLOC_REUSE_SIZE_CLASSES"},
     {Experiment::TCMALLOC_REUSE_SIZE_CLASSES, "TCMALLOC_REUSE_SIZE_CLASSES"},
-    {Experiment::TCMALLOC_HUGE_REGION_DEMAND_BASED_RELEASE, "TCMALLOC_HUGE_REGION_DEMAND_BASED_RELEASE"},
     {Experiment::TEST_ONLY_TCMALLOC_BIG_SPAN, "TEST_ONLY_TCMALLOC_BIG_SPAN"},
     {Experiment::TCMALLOC_BIG_SPAN, "TCMALLOC_BIG_SPAN"},
     {Experiment::TEST_ONLY_L3_AWARE, "TEST_ONLY_L3_AWARE"},

tcmalloc/parameters.cc

@@ -106,21 +106,6 @@ static std::atomic<int64_t>& skip_subrelease_interval_ns() {
   return v;
 }
 
-// As huge_region_demand_based_release_enabled() is determined at runtime, we
-// cannot require constant initialization for the atomic.  This avoids an
-// initialization order fiasco.
-static std::atomic<bool>& huge_region_demand_based_release_enabled() {
-  ABSL_CONST_INIT static absl::once_flag flag;
-  ABSL_CONST_INIT static std::atomic<bool> v{false};
-  absl::base_internal::LowLevelCallOnce(&flag, [&]() {
-    if (IsExperimentActive(
-            Experiment::TCMALLOC_HUGE_REGION_DEMAND_BASED_RELEASE)) {
-      v.store(true, std::memory_order_relaxed);
-    }
-  });
-  return v;
-}
-
 // Configures short and long intervals to zero by default. We expect to set them
 // to the non-zero durations once the feature is no longer experimental.
 static std::atomic<int64_t>& skip_subrelease_short_interval_ns() {
@@ -248,6 +233,9 @@ ABSL_CONST_INIT std::atomic<int64_t> Parameters::guarded_sampling_interval_(
 // TODO(b/285379004):  Remove this opt-out.
 ABSL_CONST_INIT std::atomic<bool> Parameters::release_partial_alloc_pages_(
     true);
+// TODO(b/328440160):  Remove this opt-out.
+ABSL_CONST_INIT std::atomic<bool> Parameters::huge_region_demand_based_release_(
+    false);
 // TODO(b/123345734): Remove the flag when experimentation is done.
 ABSL_CONST_INIT std::atomic<bool> Parameters::resize_size_class_max_capacity_(
     true);
@@ -320,11 +308,6 @@ absl::Duration Parameters::cache_demand_release_long_interval() {
       cache_demand_release_long_interval_ns().load(std::memory_order_relaxed));
 }
 
-bool Parameters::huge_region_demand_based_release() {
-  return huge_region_demand_based_release_enabled().load(
-      std::memory_order_relaxed);
-}
-
 bool Parameters::dense_trackers_sorted_on_spans_allocated() {
   ABSL_CONST_INIT static absl::once_flag flag;
   ABSL_CONST_INIT static std::atomic<bool> v{false};
@@ -554,7 +537,7 @@ void TCMalloc_Internal_SetHugeCacheDemandBasedRelease(bool v) {
 }
 
 void TCMalloc_Internal_SetHugeRegionDemandBasedRelease(bool v) {
-  tcmalloc::tcmalloc_internal::huge_region_demand_based_release_enabled().store(
+  Parameters::huge_region_demand_based_release_.store(
       v, std::memory_order_relaxed);
 }
 

tcmalloc/parameters.h

@@ -100,7 +100,9 @@ class Parameters {
     return release_partial_alloc_pages_.load(std::memory_order_relaxed);
   }
 
-  static bool huge_region_demand_based_release();
+  static bool huge_region_demand_based_release() {
+    return huge_region_demand_based_release_.load(std::memory_order_relaxed);
+  }
 
   static bool huge_cache_demand_based_release() {
     return huge_cache_demand_based_release_.load(std::memory_order_relaxed);
@@ -262,6 +264,7 @@ class Parameters {
   static std::atomic<double> peak_sampling_heap_growth_fraction_;
   static std::atomic<bool> per_cpu_caches_enabled_;
   static std::atomic<bool> release_partial_alloc_pages_;
+  static std::atomic<bool> huge_region_demand_based_release_;
   static std::atomic<bool> huge_cache_demand_based_release_;
   static std::atomic<bool> release_pages_from_huge_region_;
   static std::atomic<bool> resize_size_class_max_capacity_;

tcmalloc/testing/get_stats_test.cc

@@ -123,13 +123,8 @@ TEST_F(GetStatsTest, Pbtxt) {
                "tcmalloc_cache_demand_release_long_interval_ns: 300000000000"));
 #endif
   EXPECT_THAT(buf, HasSubstr("tcmalloc_release_partial_alloc_pages: true"));
-  if (Parameters::huge_region_demand_based_release()) {
-    EXPECT_THAT(buf,
-                HasSubstr("tcmalloc_huge_region_demand_based_release: true"));
-  } else {
-    EXPECT_THAT(buf,
-                HasSubstr("tcmalloc_huge_region_demand_based_release: false"));
-  }
+  EXPECT_THAT(buf,
+              HasSubstr("tcmalloc_huge_region_demand_based_release: false"));
   EXPECT_THAT(buf,
               HasSubstr("tcmalloc_huge_cache_demand_based_release: false"));
   EXPECT_THAT(buf, HasSubstr("tcmalloc_release_pages_from_huge_region: true"));
@@ -186,15 +181,9 @@ TEST_F(GetStatsTest, Parameters) {
     EXPECT_THAT(
         buf,
         HasSubstr(R"(PARAMETER tcmalloc_huge_cache_demand_based_release 0)"));
-    if (Parameters::huge_region_demand_based_release()) {
-      EXPECT_THAT(
-          buf, HasSubstr(
-                   R"(PARAMETER tcmalloc_huge_region_demand_based_release 1)"));
-    } else {
-      EXPECT_THAT(
-          buf, HasSubstr(
-                   R"(PARAMETER tcmalloc_huge_region_demand_based_release 0)"));
-    }
+    EXPECT_THAT(
+        buf,
+        HasSubstr(R"(PARAMETER tcmalloc_huge_region_demand_based_release 0)"));
     EXPECT_THAT(
         buf,
         HasSubstr(R"(PARAMETER tcmalloc_release_pages_from_huge_region 1)"));