Bug 1729815 - Remove unnecessary profiler feature "threads" - r=julienw,perftest-reviewers,AlexandruIonescu

This feature doesn't have any effect anymore.

Differential Revision: https://phabricator.services.mozilla.com/D133860

devtools/shared/performance-new/gecko-profiler-interface.js

@@ -80,7 +80,6 @@ class ActorReadyGeckoProfilerInterface {
         "stackwalk",
         "cpu",
         "responsiveness",
-        "threads",
         "leaf",
       ],
       threads: options.threads || ["GeckoMain", "Compositor"],

mozglue/baseprofiler/core/platform.cpp

@@ -231,8 +231,7 @@ static uint32_t AvailableFeatures() {
 // Default features common to all contexts (even if not available).
 static constexpr uint32_t DefaultFeatures() {
   return ProfilerFeature::Java | ProfilerFeature::JS | ProfilerFeature::Leaf |
-         ProfilerFeature::StackWalk | ProfilerFeature::Threads |
+         ProfilerFeature::StackWalk | ProfilerFeature::CPUUtilization;
-         ProfilerFeature::CPUUtilization;
 }
 
 // Extra default features when MOZ_PROFILER_STARTUP is set (even if not
@@ -604,13 +603,6 @@ class ActivePS {
     // Filter out any features unavailable in this platform/configuration.
     aFeatures &= AvailableFeatures();
 
-    // Always enable ProfilerFeature::Threads if we have a filter, because
-    // users sometimes ask to filter by a list of threads but forget to
-    // explicitly specify ProfilerFeature::Threads.
-    if (aFilterCount > 0) {
-      aFeatures |= ProfilerFeature::Threads;
-    }
-
     // Some features imply others.
     if (aFeatures & ProfilerFeature::FileIOAll) {
       aFeatures |= ProfilerFeature::MainThreadIO | ProfilerFeature::FileIO;
@@ -751,8 +743,7 @@ class ActivePS {
 
   static bool ShouldProfileThread(PSLockRef aLock, ThreadInfo* aInfo) {
     MOZ_ASSERT(sInstance);
-    return ((aInfo->IsMainThread() || FeatureThreads(aLock)) &&
+    return sInstance->ThreadSelected(aInfo->Name());
-            sInstance->ThreadSelected(aInfo->Name()));
   }
 
   PS_GET(uint32_t, Generation)

mozglue/baseprofiler/public/BaseProfilerState.h

@@ -178,46 +178,44 @@ class MOZ_RAII AutoProfilerStats {
     MACRO(9, "stackwalk", StackWalk,                                           \
           "Walk the C++ stack, not available on all platforms")                \
                                                                                \
-    MACRO(10, "threads", Threads, "Profile the registered secondary threads")  \
+    MACRO(10, "jstracer", JSTracer, "Enable tracing of the JavaScript engine") \
                                                                                \
-    MACRO(11, "jstracer", JSTracer, "Enable tracing of the JavaScript engine") \
+    MACRO(11, "jsallocations", JSAllocations,                                  \
-                                                                               \
-    MACRO(12, "jsallocations", JSAllocations,                                  \
           "Have the JavaScript engine track allocations")                      \
                                                                                \
-    MACRO(13, "nostacksampling", NoStackSampling,                              \
+    MACRO(12, "nostacksampling", NoStackSampling,                              \
           "Disable all stack sampling: Cancels \"js\", \"leaf\", "             \
           "\"stackwalk\" and labels")                                          \
                                                                                \
-    MACRO(14, "preferencereads", PreferenceReads,                              \
+    MACRO(13, "preferencereads", PreferenceReads,                              \
           "Track when preferences are read")                                   \
                                                                                \
-    MACRO(15, "nativeallocations", NativeAllocations,                          \
+    MACRO(14, "nativeallocations", NativeAllocations,                          \
           "Collect the stacks from a smaller subset of all native "            \
           "allocations, biasing towards collecting larger allocations")        \
                                                                                \
-    MACRO(16, "ipcmessages", IPCMessages,                                      \
+    MACRO(15, "ipcmessages", IPCMessages,                                      \
           "Have the IPC layer track cross-process messages")                   \
                                                                                \
-    MACRO(17, "audiocallbacktracing", AudioCallbackTracing,                    \
+    MACRO(16, "audiocallbacktracing", AudioCallbackTracing,                    \
           "Audio callback tracing")                                            \
                                                                                \
-    MACRO(18, "cpu", CPUUtilization, "CPU utilization")                        \
+    MACRO(17, "cpu", CPUUtilization, "CPU utilization")                        \
                                                                                \
-    MACRO(19, "notimerresolutionchange", NoTimerResolutionChange,              \
+    MACRO(18, "notimerresolutionchange", NoTimerResolutionChange,              \
           "Do not adjust the timer resolution for fast sampling, so that "     \
           "other Firefox timers do not get affected")                          \
                                                                                \
-    MACRO(20, "cpuallthreads", CPUAllThreads,                                  \
+    MACRO(19, "cpuallthreads", CPUAllThreads,                                  \
           "Sample the CPU utilization of all registered threads")              \
                                                                                \
-    MACRO(21, "samplingallthreads", SamplingAllThreads,                        \
+    MACRO(20, "samplingallthreads", SamplingAllThreads,                        \
           "Sample the stacks of all registered threads")                       \
                                                                                \
-    MACRO(22, "markersallthreads", MarkersAllThreads,                          \
+    MACRO(21, "markersallthreads", MarkersAllThreads,                          \
           "Record markers from all registered threads")                        \
                                                                                \
-    MACRO(23, "unregisteredthreads", UnregisteredThreads,                      \
+    MACRO(22, "unregisteredthreads", UnregisteredThreads,                      \
           "Discover and profile unregistered threads -- beware: expensive!")
 // *** Synchronize with lists in ProfilerState.h and geckoProfiler.json ***
 

mozglue/tests/TestBaseProfiler.cpp

@@ -3931,8 +3931,7 @@ void TestProfiler() {
     // Profile all registered threads.
     MOZ_RELEASE_ASSERT(filters.append(""));
     const uint32_t features = baseprofiler::ProfilerFeature::Leaf |
-                              baseprofiler::ProfilerFeature::StackWalk |
+                              baseprofiler::ProfilerFeature::StackWalk;
-                              baseprofiler::ProfilerFeature::Threads;
     baseprofiler::profiler_start(baseprofiler::BASE_PROFILER_DEFAULT_ENTRIES,
                                  BASE_PROFILER_DEFAULT_INTERVAL, features,
                                  filters.begin(), filters.length());

testing/raptor/webext/raptor/runner.js

@@ -382,7 +382,7 @@ async function startGeckoProfiling() {
   );
   const features = geckoFeatures
     ? geckoFeatures.split(",")
-    : ["js", "leaf", "stackwalk", "cpu", "threads", "responsiveness"];
+    : ["js", "leaf", "stackwalk", "cpu", "responsiveness"];
   await ext.geckoProfiler.start({
     bufferSize: geckoEntries,
     interval: geckoInterval,

toolkit/components/extensions/schemas/geckoProfiler.json

@@ -33,7 +33,6 @@
           "screenshots",
           "seqstyle",
           "stackwalk",
-          "threads",
           "jstracer",
           "jsallocations",
           "nostacksampling",

tools/profiler/core/platform.cpp

@@ -274,8 +274,8 @@ static uint32_t AvailableFeatures() {
 // Default features common to all contexts (even if not available).
 static constexpr uint32_t DefaultFeatures() {
   return ProfilerFeature::Java | ProfilerFeature::JS | ProfilerFeature::Leaf |
-         ProfilerFeature::StackWalk | ProfilerFeature::Threads |
+         ProfilerFeature::StackWalk | ProfilerFeature::CPUUtilization |
-         ProfilerFeature::CPUUtilization | ProfilerFeature::Screenshots;
+         ProfilerFeature::Screenshots;
 }
 
 // Extra default features when MOZ_PROFILER_STARTUP is set (even if not
@@ -648,13 +648,6 @@ class ActivePS {
     // Filter out any features unavailable in this platform/configuration.
     aFeatures &= AvailableFeatures();
 
-    // Always enable ProfilerFeature::Threads if we have a filter, because
-    // users sometimes ask to filter by a list of threads but forget to
-    // explicitly specify ProfilerFeature::Threads.
-    if (aFilterCount > 0) {
-      aFeatures |= ProfilerFeature::Threads;
-    }
-
     // Some features imply others.
     if (aFeatures & ProfilerFeature::FileIOAll) {
       aFeatures |= ProfilerFeature::MainThreadIO | ProfilerFeature::FileIO;
@@ -846,8 +839,7 @@ class ActivePS {
   static ThreadProfilingFeatures ProfilingFeaturesForThread(
       PSLockRef aLock, const ThreadRegistrationInfo& aInfo) {
     MOZ_ASSERT(sInstance);
-    if ((aInfo.IsMainThread() || FeatureThreads(aLock)) &&
+    if (sInstance->ThreadSelected(aInfo.Name())) {
-        sInstance->ThreadSelected(aInfo.Name())) {
       // This thread was selected by the user, record everything.
       return ThreadProfilingFeatures::Any;
     }

tools/profiler/public/ProfilerState.h

@@ -57,46 +57,44 @@
   MACRO(9, "stackwalk", StackWalk,                                           \
         "Walk the C++ stack, not available on all platforms")                \
                                                                              \
-  MACRO(10, "threads", Threads, "Profile the registered secondary threads")  \
+  MACRO(10, "jstracer", JSTracer, "Enable tracing of the JavaScript engine") \
                                                                              \
-  MACRO(11, "jstracer", JSTracer, "Enable tracing of the JavaScript engine") \
+  MACRO(11, "jsallocations", JSAllocations,                                  \
-                                                                             \
-  MACRO(12, "jsallocations", JSAllocations,                                  \
         "Have the JavaScript engine track allocations")                      \
                                                                              \
-  MACRO(13, "nostacksampling", NoStackSampling,                              \
+  MACRO(12, "nostacksampling", NoStackSampling,                              \
         "Disable all stack sampling: Cancels \"js\", \"leaf\", "             \
         "\"stackwalk\" and labels")                                          \
                                                                              \
-  MACRO(14, "preferencereads", PreferenceReads,                              \
+  MACRO(13, "preferencereads", PreferenceReads,                              \
         "Track when preferences are read")                                   \
                                                                              \
-  MACRO(15, "nativeallocations", NativeAllocations,                          \
+  MACRO(14, "nativeallocations", NativeAllocations,                          \
         "Collect the stacks from a smaller subset of all native "            \
         "allocations, biasing towards collecting larger allocations")        \
                                                                              \
-  MACRO(16, "ipcmessages", IPCMessages,                                      \
+  MACRO(15, "ipcmessages", IPCMessages,                                      \
         "Have the IPC layer track cross-process messages")                   \
                                                                              \
-  MACRO(17, "audiocallbacktracing", AudioCallbackTracing,                    \
+  MACRO(16, "audiocallbacktracing", AudioCallbackTracing,                    \
         "Audio callback tracing")                                            \
                                                                              \
-  MACRO(18, "cpu", CPUUtilization, "CPU utilization")                        \
+  MACRO(17, "cpu", CPUUtilization, "CPU utilization")                        \
                                                                              \
-  MACRO(19, "notimerresolutionchange", NoTimerResolutionChange,              \
+  MACRO(18, "notimerresolutionchange", NoTimerResolutionChange,              \
         "Do not adjust the timer resolution for sampling, so that other "    \
         "Firefox timers do not get affected")                                \
                                                                              \
-  MACRO(20, "cpuallthreads", CPUAllThreads,                                  \
+  MACRO(19, "cpuallthreads", CPUAllThreads,                                  \
         "Sample the CPU utilization of all registered threads")              \
                                                                              \
-  MACRO(21, "samplingallthreads", SamplingAllThreads,                        \
+  MACRO(20, "samplingallthreads", SamplingAllThreads,                        \
         "Sample the stacks of all registered threads")                       \
                                                                              \
-  MACRO(22, "markersallthreads", MarkersAllThreads,                          \
+  MACRO(21, "markersallthreads", MarkersAllThreads,                          \
         "Record markers from all registered threads")                        \
                                                                              \
-  MACRO(23, "unregisteredthreads", UnregisteredThreads,                      \
+  MACRO(22, "unregisteredthreads", UnregisteredThreads,                      \
         "Discover and profile unregistered threads -- beware: expensive!")
 // *** Synchronize with lists in BaseProfilerState.h and geckoProfiler.json ***
 

tools/profiler/tests/browser/browser_test_feature_ipcmessages.js

@@ -32,7 +32,7 @@ add_task(async function test_profile_feature_ipcmessges() {
   const url = BASE_URL + "simple.html";
 
   info("Open a tab while profiling IPC messages.");
-  startProfiler({ features: ["threads", "leaf", "ipcmessages"] });
+  startProfiler({ features: ["leaf", "ipcmessages"] });
   info("Started the profiler sucessfully! Now, let's open a tab.");
 
   await BrowserTestUtils.withNewTab(url, async contentBrowser => {
@@ -71,7 +71,7 @@ add_task(async function test_profile_feature_ipcmessges() {
   });
 
   info("Now open a tab without profiling IPC messages.");
-  startProfiler({ features: ["threads", "leaf"] });
+  startProfiler({ features: ["leaf"] });
 
   await BrowserTestUtils.withNewTab(url, async contentBrowser => {
     const contentPid = await SpecialPowers.spawn(

tools/profiler/tests/browser/browser_test_feature_jsallocations.js

@@ -15,7 +15,7 @@ add_task(async function test_profile_feature_jsallocations() {
     "The profiler is not currently active"
   );
 
-  startProfiler({ features: ["threads", "js", "jsallocations"] });
+  startProfiler({ features: ["js", "jsallocations"] });
 
   const url = BASE_URL + "do_work_500ms.html";
   await BrowserTestUtils.withNewTab(url, async contentBrowser => {
@@ -48,7 +48,7 @@ add_task(async function test_profile_feature_jsallocations() {
       );
     }
 
-    startProfiler({ features: ["threads", "js"] });
+    startProfiler({ features: ["js"] });
     // Now reload the tab with a clean run.
     gBrowser.reload();
     await wait(500);

tools/profiler/tests/browser/browser_test_feature_nostacksampling.js

@@ -11,7 +11,7 @@ add_task(async function test_profile_feature_nostacksampling() {
     "The profiler is not currently active"
   );
 
-  startProfiler({ features: ["threads", "js", "nostacksampling"] });
+  startProfiler({ features: ["js", "nostacksampling"] });
 
   const url = BASE_URL + "do_work_500ms.html";
   await BrowserTestUtils.withNewTab(url, async contentBrowser => {
@@ -46,7 +46,7 @@ add_task(async function test_profile_feature_nostacksampling() {
 
     // Flush out any straggling allocation markers that may have not been collected
     // yet by starting and stopping the profiler once.
-    startProfiler({ features: ["threads", "js"] });
+    startProfiler({ features: ["js"] });
 
     // Now reload the tab with a clean run.
     gBrowser.reload();

tools/profiler/tests/browser/browser_test_feature_preferencereads.js

@@ -40,7 +40,7 @@ add_task(async function test_profile_feature_preferencereads() {
     "The profiler is not currently active"
   );
 
-  startProfiler({ features: ["threads", "leaf", "preferencereads"] });
+  startProfiler({ features: ["leaf", "preferencereads"] });
 
   const url = BASE_URL + "fixed_height.html";
   await BrowserTestUtils.withNewTab(url, async contentBrowser => {
@@ -67,7 +67,7 @@ add_task(async function test_profile_feature_preferencereads() {
       );
     }
 
-    startProfiler({ features: ["threads", "leaf"] });
+    startProfiler({ features: ["leaf"] });
     // Now reload the tab with a clean run.
     await ContentTask.spawn(contentBrowser, null, () => {
       return new Promise(resolve => {

tools/profiler/tests/chrome/test_profile_worker.html

@@ -22,7 +22,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1428076
 const settings = {
   entries: 1000000, // 9MB
   interval: 1, // ms
-  features: ["js", "threads", "leaf", "stackwalk", "cpu"],
+  features: ["js", "leaf", "stackwalk", "cpu"],
   threads: ["GeckoMain", "Compositor", "Worker"], // most common combination
 };
 

tools/profiler/tests/chrome/test_profile_worker_bug_1428076.html

@@ -24,7 +24,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=1428076
 const settings = {
   entries: 1000000, // 9MB
   interval: 1, // ms
-  features: ["js", "threads", "leaf", "stackwalk"],
+  features: ["js", "leaf", "stackwalk"],
   threads: ["GeckoMain", "Compositor", "Worker"], // most common combination
 };
 

tools/profiler/tests/gtest/GeckoProfiler.cpp

@@ -1509,7 +1509,7 @@ TEST(GeckoProfiler, FeaturesAndParams)
 
   // Try a couple of features and filters.
   {
-    uint32_t features = ProfilerFeature::JS | ProfilerFeature::Threads;
+    uint32_t features = ProfilerFeature::JS;
     const char* filters[] = {"GeckoMain", "Compositor"};
 
     profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
@@ -1545,9 +1545,7 @@ TEST(GeckoProfiler, FeaturesAndParams)
     ASSERT_TRUE(profiler_feature_active(ProfilerFeature::MainThreadIO));
     ASSERT_TRUE(profiler_feature_active(ProfilerFeature::IPCMessages));
 
-    // Profiler::Threads is added because filters has multiple entries.
+    ActiveParamsCheck(int(PowerOfTwo32(999999).Value()), 3, features, filters,
-    ActiveParamsCheck(PowerOfTwo32(999999).Value(), 3,
-                      features | ProfilerFeature::Threads, filters,
                       MOZ_ARRAY_LENGTH(filters), 123, Some(25.0));
 
     profiler_stop();
@@ -1568,9 +1566,7 @@ TEST(GeckoProfiler, FeaturesAndParams)
     ASSERT_TRUE(profiler_feature_active(ProfilerFeature::MainThreadIO));
     ASSERT_TRUE(profiler_feature_active(ProfilerFeature::IPCMessages));
 
-    // Profiler::Threads is added because filters has multiple entries.
+    ActiveParamsCheck(int(PowerOfTwo32(999999).Value()), 3, features, filters,
-    ActiveParamsCheck(PowerOfTwo32(999999).Value(), 3,
-                      features | ProfilerFeature::Threads, filters,
                       MOZ_ARRAY_LENGTH(filters), 0, Nothing());
 
     profiler_stop();
@@ -1612,8 +1608,7 @@ TEST(GeckoProfiler, FeaturesAndParams)
 
     // Entries and intervals go to defaults if 0 is specified.
     ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
-                      PROFILER_DEFAULT_INTERVAL,
+                      PROFILER_DEFAULT_INTERVAL, features, filters,
-                      features | ProfilerFeature::Threads, filters,
                       MOZ_ARRAY_LENGTH(filters), 0, Nothing());
 
     profiler_stop();
@@ -1632,7 +1627,7 @@ TEST(GeckoProfiler, EnsureStarted)
 {
   InactiveFeaturesAndParamsCheck();
 
-  uint32_t features = ProfilerFeature::JS | ProfilerFeature::Threads;
+  uint32_t features = ProfilerFeature::JS;
   const char* filters[] = {"GeckoMain", "Compositor"};
   {
     // Inactive -> Active
@@ -1770,7 +1765,7 @@ TEST(GeckoProfiler, DifferentThreads)
   // Control the profiler on a background thread and verify flags on the
   // main thread.
   {
-    uint32_t features = ProfilerFeature::JS | ProfilerFeature::Threads;
+    uint32_t features = ProfilerFeature::JS;
     const char* filters[] = {"GeckoMain", "Compositor"};
 
     thread->Dispatch(
@@ -1802,7 +1797,7 @@ TEST(GeckoProfiler, DifferentThreads)
   // Control the profiler on the main thread and verify flags on a
   // background thread.
   {
-    uint32_t features = ProfilerFeature::JS | ProfilerFeature::Threads;
+    uint32_t features = ProfilerFeature::JS;
     const char* filters[] = {"GeckoMain", "Compositor"};
 
     profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
@@ -3348,7 +3343,7 @@ PROFILER_DEFINE_COUNT_TOTAL(TestCounter2, COUNTER_NAME2, COUNTER_DESCRIPTION2);
 
 TEST(GeckoProfiler, Counters)
 {
-  uint32_t features = ProfilerFeature::Threads;
+  uint32_t features = 0;
   const char* filters[] = {"GeckoMain"};
 
   // We will record some counter values, and check that they're present (and no
@@ -3514,8 +3509,6 @@ TEST(GeckoProfiler, GetProfile)
   ASSERT_TRUE(activeFeatures.isSome());
   // Not all platforms support stack-walking.
   const bool hasStackWalk = ProfilerFeature::HasStackWalk(*activeFeatures);
-  // "threads" may automatically be added when `filters` is not empty.
-  const bool hasThreads = ProfilerFeature::HasThreads(*activeFeatures);
 
   UniquePtr<char[]> profile = profiler_get_profile();
   JSONOutputCheck(profile.get(), [&](const Json::Value& aRoot) {
@@ -3525,14 +3518,10 @@ TEST(GeckoProfiler, GetProfile)
       {
         GET_JSON(features, configuration["features"], Array);
         {
-          EXPECT_EQ(features.size(),
+          EXPECT_EQ(features.size(), (hasStackWalk ? 1u : 0u));
-                    (hasStackWalk ? 1u : 0u) + (hasThreads ? 1u : 0u));
           if (hasStackWalk) {
             EXPECT_JSON_ARRAY_CONTAINS(features, String, "stackwalk");
           }
-          if (hasThreads) {
-            EXPECT_JSON_ARRAY_CONTAINS(features, String, "threads");
-          }
         }
         GET_JSON(threads, configuration["threads"], Array);
         {
@@ -3735,7 +3724,7 @@ TEST(GeckoProfiler, SuspendAndSample)
 
   DoSuspendAndSample(ProfilerThreadId{}, thread);
 
-  uint32_t features = ProfilerFeature::JS | ProfilerFeature::Threads;
+  uint32_t features = ProfilerFeature::JS;
   const char* filters[] = {"GeckoMain", "Compositor"};
 
   profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
@@ -4402,7 +4391,7 @@ TEST(GeckoProfiler, AllThreads)
 
     ASSERT_TRUE(!profiler_is_active());
 
-    uint32_t features = ProfilerFeature::StackWalk | ProfilerFeature::Threads;
+    uint32_t features = ProfilerFeature::StackWalk;
     std::string featuresString = "Features: StackWalk Threads";
     if (threadCPU) {
       features |= ProfilerFeature::CPUAllThreads;

tools/profiler/tests/shared-head.js

@@ -21,7 +21,7 @@ var { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
 const defaultSettings = {
   entries: 8 * 1024 * 1024, // 8M entries = 64MB
   interval: 1, // ms
-  features: ["threads"],
+  features: [],
   threads: ["GeckoMain"],
 };
 
@@ -44,7 +44,7 @@ function startProfiler(callersSettings) {
 
 function startProfilerForMarkerTests() {
   startProfiler({
-    features: ["threads", "nostacksampling", "js"],
+    features: ["nostacksampling", "js"],
     threads: ["GeckoMain", "DOM Worker"],
   });
 }

tools/profiler/tests/xpcshell/test_active_configuration.js

@@ -19,7 +19,7 @@ function run_test() {
     const entries = 10000;
     const interval = 1;
     const threads = ["GeckoMain"];
-    const features = ["js", "leaf", "threads"];
+    const features = ["js", "leaf"];
     const activeTabID = 123;
     Services.profiler.StartProfiler(
       entries,
@@ -61,7 +61,7 @@ function run_test() {
     const entries = 20000;
     const interval = 0.5;
     const threads = ["GeckoMain", "DOM Worker"];
-    const features = ["threads"];
+    const features = [];
     const activeTabID = 111;
     const duration = 20;
 

tools/profiler/tests/xpcshell/test_feature_nativeallocations.js

@@ -26,7 +26,7 @@ add_task(async () => {
     startProfiler({
       // Only instrument the main thread.
       threads: ["GeckoMain"],
-      features: ["threads", "leaf", "nativeallocations"],
+      features: ["leaf", "nativeallocations"],
     });
 
     info(
@@ -71,7 +71,7 @@ add_task(async () => {
 
   info("Restart the profiler, to ensure that we get no more allocations.");
   {
-    startProfiler({ features: ["threads", "leaf"] });
+    startProfiler({ features: ["leaf"] });
     info("Do some work again.");
     doWork();
     info("Wait for the periodic sampling.");