gin/gin_features.cc

   1 // Copyright 2017 The Chromium Authors
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "gin/gin_features.h"
   6 #include "base/metrics/field_trial_params.h"
   7
   8 namespace features {
   9
  10 // Enable code space compaction when finalizing a full GC with stack.
  11 BASE_FEATURE(kV8CompactCodeSpaceWithStack,
  12              "V8CompactCodeSpaceWithStack",
  13              base::FEATURE_ENABLED_BY_DEFAULT);
  14
  15 // Enable compaction when finalizing a full GC with stack.
  16 BASE_FEATURE(kV8CompactWithStack,
  17              "V8CompactWithStack",
  18              base::FEATURE_ENABLED_BY_DEFAULT);
  19
  20 // Enables compaction of maps in a full GC.
  21 BASE_FEATURE(kV8CompactMaps,
  22              "V8CompactMaps",
  23              base::FEATURE_DISABLED_BY_DEFAULT);
  24
  25 // Crashes on evacuation failures in a full GC instead of aborting evacuation.
  26 BASE_FEATURE(kV8CrashOnEvacuationFailure,
  27              "V8CrashOnEvacuationFailure",
  28              base::FEATURE_DISABLED_BY_DEFAULT);
  29
  30 // Enables a separate heap space for all map objects.
  31 BASE_FEATURE(kV8UseMapSpace, "V8UseMapSpace", base::FEATURE_ENABLED_BY_DEFAULT);
  32
  33 // Enables optimization of JavaScript in V8.
  34 BASE_FEATURE(kV8OptimizeJavascript,
  35              "V8OptimizeJavascript",
  36              base::FEATURE_ENABLED_BY_DEFAULT);
  37
  38 // Enables flushing of JS bytecode in V8.
  39 BASE_FEATURE(kV8FlushBytecode,
  40              "V8FlushBytecode",
  41              base::FEATURE_ENABLED_BY_DEFAULT);
  42 const base::FeatureParam<int> kV8FlushBytecodeOldAge{
  43     &kV8FlushBytecode, "V8FlushBytecodeOldAge", 5};
  44
  45 // Enables flushing of baseline code in V8.
  46 BASE_FEATURE(kV8FlushBaselineCode,
  47              "V8FlushBaselineCode",
  48              base::FEATURE_DISABLED_BY_DEFAULT);
  49
  50 // Enables finalizing streaming JS compilations on a background thread.
  51 BASE_FEATURE(kV8OffThreadFinalization,
  52              "V8OffThreadFinalization",
  53              base::FEATURE_ENABLED_BY_DEFAULT);
  54
  55 // Enables lazy feedback allocation in V8.
  56 BASE_FEATURE(kV8LazyFeedbackAllocation,
  57              "V8LazyFeedbackAllocation",
  58              base::FEATURE_ENABLED_BY_DEFAULT);
  59
  60 // Enables per-context marking worklists in V8 GC.
  61 BASE_FEATURE(kV8PerContextMarkingWorklist,
  62              "V8PerContextMarkingWorklist",
  63              base::FEATURE_DISABLED_BY_DEFAULT);
  64
  65 // Enables flushing of the instruction cache for the embedded blob.
  66 BASE_FEATURE(kV8FlushEmbeddedBlobICache,
  67              "V8FlushEmbeddedBlobICache",
  68              base::FEATURE_DISABLED_BY_DEFAULT);
  69
  70 // Enables reduced number of concurrent marking tasks.
  71 BASE_FEATURE(kV8ReduceConcurrentMarkingTasks,
  72              "V8ReduceConcurrentMarkingTasks",
  73              base::FEATURE_DISABLED_BY_DEFAULT);
  74
  75 // Disables reclaiming of unmodified wrappers objects.
  76 BASE_FEATURE(kV8NoReclaimUnmodifiedWrappers,
  77              "V8NoReclaimUnmodifiedWrappers",
  78              base::FEATURE_DISABLED_BY_DEFAULT);
  79
  80 // Enables W^X code memory protection in V8.
  81 // This is enabled in V8 by default. To test the performance impact, we are
  82 // going to disable this feature in a finch experiment.
  83 BASE_FEATURE(kV8CodeMemoryWriteProtection,
  84              "V8CodeMemoryWriteProtection",
  85              base::FEATURE_ENABLED_BY_DEFAULT);
  86
  87 // Enables fallback to a breadth-first regexp engine on excessive backtracking.
  88 BASE_FEATURE(kV8ExperimentalRegexpEngine,
  89              "V8ExperimentalRegexpEngine",
  90              base::FEATURE_ENABLED_BY_DEFAULT);
  91
  92 // Enables experimental Maglev compiler.
  93 BASE_FEATURE(kV8Maglev, "V8Maglev", base::FEATURE_DISABLED_BY_DEFAULT);
  94
  95 // Enables Sparkplug compiler. Note that this only sets the V8 flag when
  96 // manually overridden; otherwise it defers to whatever the V8 default is.
  97 BASE_FEATURE(kV8Sparkplug, "V8Sparkplug", base::FEATURE_ENABLED_BY_DEFAULT);
  98
  99 // Enables the concurrent Sparkplug compiler.
 100 BASE_FEATURE(kV8ConcurrentSparkplug,
 101              "V8ConcurrentSparkplug",
 102              base::FEATURE_DISABLED_BY_DEFAULT);
 103 const base::FeatureParam<int> kV8ConcurrentSparkplugMaxThreads{
 104     &kV8ConcurrentSparkplug, "V8ConcurrentSparkplugMaxThreads", 0};
 105 BASE_FEATURE(kV8ConcurrentSparkplugHighPriorityThreads,
 106              "V8ConcurrentSparkplugHighPriorityThreads",
 107              base::FEATURE_DISABLED_BY_DEFAULT);
 108 // Makes sure the experimental Sparkplug compiler is only enabled if short
 109 // builtin calls are enabled too.
 110 BASE_FEATURE(kV8SparkplugNeedsShortBuiltinCalls,
 111              "V8SparkplugNeedsShortBuiltinCalls",
 112              base::FEATURE_DISABLED_BY_DEFAULT);
 113
 114 // Enables short builtin calls feature.
 115 BASE_FEATURE(kV8ShortBuiltinCalls,
 116              "V8ShortBuiltinCalls",
 117              base::FEATURE_ENABLED_BY_DEFAULT);
 118
 119 // Enables fast API calls in TurboFan.
 120 BASE_FEATURE(kV8TurboFastApiCalls,
 121              "V8TurboFastApiCalls",
 122              base::FEATURE_ENABLED_BY_DEFAULT);
 123
 124 // Artificially delays script execution.
 125 BASE_FEATURE(kV8ScriptAblation,
 126              "V8ScriptAblation",
 127              base::FEATURE_DISABLED_BY_DEFAULT);
 128 const base::FeatureParam<int> kV8ScriptDelayOnceMs{&kV8ScriptAblation,
 129                                                    "V8ScriptDelayOnceMs", 0};
 130 const base::FeatureParam<int> kV8ScriptDelayMs{&kV8ScriptAblation,
 131                                                "V8ScriptDelayMs", 0};
 132 const base::FeatureParam<double> kV8ScriptDelayFraction{
 133     &kV8ScriptAblation, "V8ScriptDelayFraction", 0.0};
 134
 135 // Enables slow histograms that provide detailed information at increased
 136 // runtime overheads.
 137 BASE_FEATURE(kV8SlowHistograms,
 138              "V8SlowHistograms",
 139              base::FEATURE_DISABLED_BY_DEFAULT);
 140 // Multiple finch experiments might use slow-histograms. We introduce
 141 // separate feature flags to circumvent finch limitations.
 142 BASE_FEATURE(kV8SlowHistogramsCodeMemoryWriteProtection,
 143              "V8SlowHistogramsCodeMemoryWriteProtection",
 144              base::FEATURE_DISABLED_BY_DEFAULT);
 145 BASE_FEATURE(kV8SlowHistogramsSparkplug,
 146              "V8SlowHistogramsSparkplug",
 147              base::FEATURE_DISABLED_BY_DEFAULT);
 148 BASE_FEATURE(kV8SlowHistogramsSparkplugAndroid,
 149              "V8SlowHistogramsSparkplugAndroid",
 150              base::FEATURE_DISABLED_BY_DEFAULT);
 151 BASE_FEATURE(kV8SlowHistogramsScriptAblation,
 152              "V8SlowHistogramsScriptAblation",
 153              base::FEATURE_DISABLED_BY_DEFAULT);
 154
 155 BASE_FEATURE(kV8DelayMemoryReducer,
 156              "V8DelayMemoryReducer",
 157              base::FEATURE_DISABLED_BY_DEFAULT);
 158 const base::FeatureParam<base::TimeDelta> kV8MemoryReducerStartDelay{
 159     &kV8DelayMemoryReducer, "delay", base::Seconds(8)};
 160
 161 }  // namespace features