Version 3.0.2.

src/runtime-profiler.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 50 matching lines @@
  private:
   void Destroy();
   static void WeakCallback(v8::Persistent<v8::Value> object, void* data);
 
   PendingListNode* next_;
   Handle<Object> function_;  // Weak handle.
   int64_t start_;
 };
 
 
-enum SamplerState {
-  IN_NON_JS_STATE = 0,
-  IN_JS_STATE = 1
-};
-
-
 // Optimization sampler constants.
 static const int kSamplerFrameCount = 2;
 static const int kSamplerFrameWeight[kSamplerFrameCount] = { 2, 1 };
 static const int kSamplerWindowSize = 16;
 
-static const int kSamplerTicksBetweenThresholdAdjustment = 32;
+static const int kSamplerTicksDelta = 32;
 
 static const int kSamplerThresholdInit = 3;
 static const int kSamplerThresholdMin = 1;
 static const int kSamplerThresholdDelta = 1;
 
 static const int kSamplerThresholdSizeFactorInit = 3;
 static const int kSamplerThresholdSizeFactorMin = 1;
 static const int kSamplerThresholdSizeFactorDelta = 1;
 
 static const int kSizeLimit = 1500;
 
 static int sampler_threshold = kSamplerThresholdInit;
 static int sampler_threshold_size_factor = kSamplerThresholdSizeFactorInit;
 
-static int sampler_ticks_until_threshold_adjustment =
-    kSamplerTicksBetweenThresholdAdjustment;
-
-// The ratio of ticks spent in JS code in percent.
-static Atomic32 js_ratio;
 
 // The JSFunctions in the sampler window are not GC safe. Old-space
 // pointers are not cleared during mark-sweep collection and therefore
 // the window might contain stale pointers. The window is updated on
 // scavenges and (parts of it) cleared on mark-sweep and
 // mark-sweep-compact.
 static Object* sampler_window[kSamplerWindowSize] = { NULL, };
 static int sampler_window_position = 0;
 static int sampler_window_weight[kSamplerWindowSize] = { 0, };
 
@@ skipping 153 matching lines @@
     }
     delete current;
     current = next;
   }
   optimize_soon_list = NULL;
 
   // Run through the JavaScript frames and collect them. If we already
   // have a sample of the function, we mark it for optimizations
   // (eagerly or lazily).
   JSFunction* samples[kSamplerFrameCount];
-  int sample_count = 0;
-  int frame_count = 0;
+  int count = 0;
   for (JavaScriptFrameIterator it;
-       frame_count++ < kSamplerFrameCount && !it.done();
+       count < kSamplerFrameCount && !it.done();
        it.Advance()) {
     JavaScriptFrame* frame = it.frame();
     JSFunction* function = JSFunction::cast(frame->function());
-
-    // Adjust threshold each time we have processed
-    // a certain number of ticks.
-    if (sampler_ticks_until_threshold_adjustment > 0) {
-      sampler_ticks_until_threshold_adjustment--;
-      if (sampler_ticks_until_threshold_adjustment <= 0) {
-        // If the threshold is not already at the minimum
-        // modify and reset the ticks until next adjustment.
-        if (sampler_threshold > kSamplerThresholdMin) {
-          sampler_threshold -= kSamplerThresholdDelta;
-          sampler_ticks_until_threshold_adjustment =
-              kSamplerTicksBetweenThresholdAdjustment;
-        }
-      }
+    int function_size = function->shared()->SourceSize();
+    int threshold_size_factor;
+    if (function_size > kSizeLimit) {
+      threshold_size_factor = sampler_threshold_size_factor;
+    } else {
+      threshold_size_factor = 1;
     }
 
+    int threshold = sampler_threshold * threshold_size_factor;
+    samples[count++] = function;
     if (function->IsMarkedForLazyRecompilation()) {
       Code* unoptimized = function->shared()->code();
       int nesting = unoptimized->allow_osr_at_loop_nesting_level();
       if (nesting == 0) AttemptOnStackReplacement(function);
       int new_nesting = Min(nesting + 1, Code::kMaxLoopNestingMarker);
       unoptimized->set_allow_osr_at_loop_nesting_level(new_nesting);
-    }
-
-    // Do not record non-optimizable functions.
-    if (!IsOptimizable(function)) continue;
-    samples[sample_count++] = function;
-
-    int function_size = function->shared()->SourceSize();
-    int threshold_size_factor = (function_size > kSizeLimit)
-        ? sampler_threshold_size_factor
-        : 1;
-
-    int threshold = sampler_threshold * threshold_size_factor;
-    int current_js_ratio = NoBarrier_Load(&js_ratio);
-
-    // Adjust threshold depending on the ratio of time spent
-    // in JS code.
-    if (current_js_ratio < 20) {
-      // If we spend less than 20% of the time in JS code,
-      // do not optimize.
-      continue;
-    } else if (current_js_ratio < 75) {
-      // Below 75% of time spent in JS code, only optimize very
-      // frequently used functions.
-      threshold *= 3;
-    }
-
-    if (LookupSample(function) >= threshold) {
-      Optimize(function, false, 0);
-      CompilationCache::MarkForEagerOptimizing(Handle<JSFunction>(function));
+    } else if (LookupSample(function) >= threshold) {
+      if (IsOptimizable(function)) {
+        Optimize(function, false, 0);
+        CompilationCache::MarkForEagerOptimizing(Handle<JSFunction>(function));
+      }
     }
   }
 
   // Add the collected functions as samples. It's important not to do
   // this as part of collecting them because this will interfere with
   // the sample lookup in case of recursive functions.
-  for (int i = 0; i < sample_count; i++) {
+  for (int i = 0; i < count; i++) {
     AddSample(samples[i], kSamplerFrameWeight[i]);
   }
 }
 
 
 void RuntimeProfiler::OptimizeSoon(JSFunction* function) {
   if (!IsOptimizable(function)) return;
   PendingListNode* node = new PendingListNode(function);
   node->set_next(optimize_soon_list);
   optimize_soon_list = node;
 }
 
 
-static void UpdateStateRatio(SamplerState current_state) {
-  static const int kStateWindowSize = 128;
-  static SamplerState state_window[kStateWindowSize];
-  static int state_window_position = 0;
-  static int state_counts[2] = { kStateWindowSize, 0 };
-
-  SamplerState old_state = state_window[state_window_position];
-  state_counts[old_state]--;
-  state_window[state_window_position] = current_state;
-  state_counts[current_state]++;
-  ASSERT(IsPowerOf2(kStateWindowSize));
-  state_window_position = (state_window_position + 1) &
-      (kStateWindowSize - 1);
-  NoBarrier_Store(&js_ratio, state_counts[IN_JS_STATE] * 100 /
-                  kStateWindowSize);
-}
-
-
 void RuntimeProfiler::NotifyTick() {
-  // Record state sample.
-  SamplerState state = Top::IsInJSState()
-      ? IN_JS_STATE
-      : IN_NON_JS_STATE;
-  UpdateStateRatio(state);
   StackGuard::RequestRuntimeProfilerTick();
 }
 
 
 void RuntimeProfiler::MarkCompactPrologue(bool is_compacting) {
   if (is_compacting) {
     // Clear all samples before mark-sweep-compact because every
     // function might move.
     ClearSampleBuffer();
   } else {
@@ skipping 12 matching lines @@
 void RuntimeProfiler::Setup() {
   ClearSampleBuffer();
   // If the ticker hasn't already started, make sure to do so to get
   // the ticks for the runtime profiler.
   if (IsEnabled()) Logger::EnsureTickerStarted();
 }
 
 
 void RuntimeProfiler::Reset() {
   sampler_threshold = kSamplerThresholdInit;
-  sampler_ticks_until_threshold_adjustment =
-      kSamplerTicksBetweenThresholdAdjustment;
   sampler_threshold_size_factor = kSamplerThresholdSizeFactorInit;
 }
 
 
 void RuntimeProfiler::TearDown() {
   // Nothing to do.
 }
 
 
 Object** RuntimeProfiler::SamplerWindowAddress() {
@@ skipping 22 matching lines @@
       } else {
         if (Top::WaitForJSState()) return true;
       }
     }
   }
   return false;
 }
 
 
 } }  // namespace v8::internal