Perform scavenge in idle tasks.

src/heap/gc-idle-time-handler.cc

Index: src/heap/gc-idle-time-handler.cc
diff --git a/src/heap/gc-idle-time-handler.cc b/src/heap/gc-idle-time-handler.cc
index f836a062849319c9ee9e1759774fbab087994e04..f77c015bf5bef1530e062e91b8f74dd280905b07 100644
--- a/src/heap/gc-idle-time-handler.cc
+++ b/src/heap/gc-idle-time-handler.cc
@@ -32,9 +32,6 @@ void GCIdleTimeAction::Print() {
         PrintF("; finalized marking");
       }
       break;
-    case DO_SCAVENGE:
-      PrintF("scavenge");
-      break;
     case DO_FULL_GC:
       PrintF("full GC");
       break;
@@ -53,11 +50,6 @@ void GCIdleTimeHeapState::Print() {
          mark_compact_speed_in_bytes_per_ms);
   PrintF("incremental_marking_speed=%" V8_PTR_PREFIX "d ",
          incremental_marking_speed_in_bytes_per_ms);
-  PrintF("scavenge_speed=%" V8_PTR_PREFIX "d ", scavenge_speed_in_bytes_per_ms);
-  PrintF("new_space_size=%" V8_PTR_PREFIX "d ", used_new_space_size);
-  PrintF("new_space_capacity=%" V8_PTR_PREFIX "d ", new_space_capacity);
-  PrintF("new_space_allocation_throughput=%" V8_PTR_PREFIX "d ",
-         new_space_allocation_throughput_in_bytes_per_ms);
 }
 
 
@@ -107,79 +99,6 @@ size_t GCIdleTimeHandler::EstimateFinalIncrementalMarkCompactTime(
 }
 
 
-bool GCIdleTimeHandler::ShouldDoScavenge(
-    size_t idle_time_in_ms, size_t new_space_size, size_t used_new_space_size,
-    size_t scavenge_speed_in_bytes_per_ms,
-    size_t new_space_allocation_throughput_in_bytes_per_ms) {
-  if (idle_time_in_ms >= kMinBackgroundIdleTime) {
-    // It is better to do full GC for the background tab.
-    return false;
-  }
-
-  // Calculates how much memory are we able to scavenge in
-  // kMaxFrameRenderingIdleTime ms. If scavenge_speed_in_bytes_per_ms is 0 we
-  // will take care of this later.
-  size_t idle_new_space_allocation_limit =
-      kMaxFrameRenderingIdleTime * scavenge_speed_in_bytes_per_ms;
-
-  // If the limit is larger than the new space size, then scavenging used to be
-  // really fast. We can take advantage of the whole new space.
-  if (idle_new_space_allocation_limit > new_space_size) {
-    idle_new_space_allocation_limit = new_space_size;
-  }
-
-  // We do not know the allocation throughput before the first scavenge.
-  // TODO(hpayer): Estimate allocation throughput before the first scavenge.
-  if (new_space_allocation_throughput_in_bytes_per_ms > 0) {
-    // We have to trigger scavenge before we reach the end of new space.
-    size_t adjust_limit = new_space_allocation_throughput_in_bytes_per_ms *
-                          kTimeUntilNextIdleEvent;
-    if (adjust_limit > idle_new_space_allocation_limit) {
-      idle_new_space_allocation_limit = 0;
-    } else {
-      idle_new_space_allocation_limit -= adjust_limit;
-    }
-  }
-
-  // The allocated new space limit to trigger a scavange has to be at least
-  // kMinimumNewSpaceSizeToPerformScavenge.
-  if (idle_new_space_allocation_limit < kMinimumNewSpaceSizeToPerformScavenge) {
-    idle_new_space_allocation_limit = kMinimumNewSpaceSizeToPerformScavenge;
-  }
-
-  // Set an initial scavenge speed if it is unknown.
-  if (scavenge_speed_in_bytes_per_ms == 0) {
-    scavenge_speed_in_bytes_per_ms = kInitialConservativeScavengeSpeed;
-  }
-
-  // We apply a max factor to the new space size to make sure that a slowly
-  // allocating application still leaves enough of wiggle room to schedule a
-  // scavenge.
-  size_t max_limit;
-  const double kMaxNewSpaceSizeFactorLongIdleTimes = 0.5;
-  const double kMaxNewSpaceSizeFactorShortIdleTimes = 0.8;
-  if (idle_time_in_ms > kMaxFrameRenderingIdleTime) {
-    max_limit = static_cast<size_t>(new_space_size *
-                                    kMaxNewSpaceSizeFactorLongIdleTimes);
-  } else {
-    max_limit = static_cast<size_t>(new_space_size *
-                                    kMaxNewSpaceSizeFactorShortIdleTimes);
-  }
-  idle_new_space_allocation_limit =
-      Min(idle_new_space_allocation_limit, max_limit);
-
-  // We perform a scavenge if we are over the idle new space limit and
-  // a scavenge fits into the given idle time bucket.
-  if (idle_new_space_allocation_limit <= used_new_space_size) {
-    if (used_new_space_size / scavenge_speed_in_bytes_per_ms <=
-        idle_time_in_ms) {
-      return true;
-    }
-  }
-  return false;
-}
-
-
 bool GCIdleTimeHandler::ShouldDoMarkCompact(
     size_t idle_time_in_ms, size_t size_of_objects,
     size_t mark_compact_speed_in_bytes_per_ms) {
@@ -259,14 +178,6 @@ GCIdleTimeAction GCIdleTimeHandler::Compute(double idle_time_in_ms,
     return NothingOrDone(idle_time_in_ms);
   }
 
-  if (ShouldDoScavenge(
-          static_cast<size_t>(idle_time_in_ms), heap_state.new_space_capacity,
-          heap_state.used_new_space_size,
-          heap_state.scavenge_speed_in_bytes_per_ms,
-          heap_state.new_space_allocation_throughput_in_bytes_per_ms)) {
-    return GCIdleTimeAction::Scavenge();
-  }
-
   if (!FLAG_incremental_marking || heap_state.incremental_marking_stopped) {
     return GCIdleTimeAction::Done();
   }