Reviewers: Michael Starzinger, danno,
Description:
Simplifying GC heuristics, deleted old generation allocation limit.
BUG=
Please review this at https://codereview.chromium.org/14731029/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files:
M src/heap.h
M src/heap.cc
Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index
35b201f2f1b53a23d59ac4f1ae87bcd1b44c877f..f7c2508020b52ad3564904ee048b53ec15d8e018
100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -118,8 +118,7 @@ Heap::Heap()
disallow_allocation_failure_(false),
#endif // DEBUG
new_space_high_promotion_mode_active_(false),
- old_gen_promotion_limit_(kMinimumPromotionLimit),
- old_gen_allocation_limit_(kMinimumAllocationLimit),
+
old_generation_allocation_limit_(kMinimumOldGenerationAllocationLimit),
size_of_old_gen_at_last_old_space_gc_(0),
external_allocation_limit_(0),
amount_of_external_allocated_memory_(0),
@@ -282,7 +281,7 @@ GarbageCollector
Heap::SelectGarbageCollector(AllocationSpace space,
}
// Is enough data promoted to justify a global GC?
- if (OldGenerationPromotionLimitReached()) {
+ if (OldGenerationAllocationLimitReached()) {
isolate_->counters()->gc_compactor_caused_by_promoted_data()->Increment();
*reason = "promotion limit reached";
return MARK_COMPACTOR;
@@ -916,10 +915,8 @@ bool Heap::PerformGarbageCollection(GarbageCollector
collector,
size_of_old_gen_at_last_old_space_gc_ = PromotedSpaceSizeOfObjects();
- old_gen_promotion_limit_ =
- OldGenPromotionLimit(size_of_old_gen_at_last_old_space_gc_);
- old_gen_allocation_limit_ =
- OldGenAllocationLimit(size_of_old_gen_at_last_old_space_gc_);
+ old_generation_allocation_limit_ =
+
OldGenerationAllocationLimit(size_of_old_gen_at_last_old_space_gc_);
old_gen_exhausted_ = false;
} else {
@@ -5875,10 +5872,8 @@ void Heap::ReportHeapStatistics(const char* title) {
USE(title);
PrintF(">>>>>> =============== %s (%d) =============== >>>>>>\n",
title, gc_count_);
- PrintF("old_gen_promotion_limit_ %" V8_PTR_PREFIX "d\n",
- old_gen_promotion_limit_);
- PrintF("old_gen_allocation_limit_ %" V8_PTR_PREFIX "d\n",
- old_gen_allocation_limit_);
+ PrintF("old_generation_allocation_limit_ %" V8_PTR_PREFIX "d\n",
+ old_generation_allocation_limit_);
PrintF("\n");
PrintF("Number of handles : %d\n",
HandleScope::NumberOfHandles(isolate_));
Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index
e4cb1ef8907ae493550e69f3ac9930d059eff7b0..f9a64d4fae6de5f74d8b4d6b78424bde6d850e02
100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -1547,39 +1547,23 @@ class Heap {
return PromotedSpaceSizeOfObjects() + PromotedExternalMemorySize();
}
- // True if we have reached the allocation limit in the old generation
that
- // should force the next GC (caused normally) to be a full one.
- inline bool OldGenerationPromotionLimitReached() {
- return PromotedTotalSize() > old_gen_promotion_limit_;
- }
-
inline intptr_t OldGenerationSpaceAvailable() {
- return old_gen_allocation_limit_ - PromotedTotalSize();
+ return old_generation_allocation_limit_ - PromotedTotalSize();
}
inline intptr_t OldGenerationCapacityAvailable() {
return max_old_generation_size_ - PromotedTotalSize();
}
- static const intptr_t kMinimumPromotionLimit = 5 * Page::kPageSize;
- static const intptr_t kMinimumAllocationLimit =
+ static const intptr_t kMinimumOldGenerationAllocationLimit =
8 * (Page::kPageSize > MB ? Page::kPageSize : MB);
- intptr_t OldGenPromotionLimit(intptr_t old_gen_size) {
+ intptr_t OldGenerationAllocationLimit(intptr_t old_gen_size) {
const int divisor = FLAG_stress_compaction ? 10 :
new_space_high_promotion_mode_active_ ? 1 : 3;
intptr_t limit =
- Max(old_gen_size + old_gen_size / divisor, kMinimumPromotionLimit);
- limit += new_space_.Capacity();
- intptr_t halfway_to_the_max = (old_gen_size +
max_old_generation_size_) / 2;
- return Min(limit, halfway_to_the_max);
- }
-
- intptr_t OldGenAllocationLimit(intptr_t old_gen_size) {
- const int divisor = FLAG_stress_compaction ? 8 :
- new_space_high_promotion_mode_active_ ? 1 : 2;
- intptr_t limit =
- Max(old_gen_size + old_gen_size / divisor,
kMinimumAllocationLimit);
+ Max(old_gen_size + old_gen_size / divisor,
+ kMinimumOldGenerationAllocationLimit);
limit += new_space_.Capacity();
intptr_t halfway_to_the_max = (old_gen_size +
max_old_generation_size_) / 2;
return Min(limit, halfway_to_the_max);
@@ -1652,22 +1636,14 @@ class Heap {
if (FLAG_stress_compaction && (gc_count_ & 1) != 0) return true;
- intptr_t total_promoted = PromotedTotalSize();
-
- intptr_t adjusted_promotion_limit =
- old_gen_promotion_limit_ - new_space_.Capacity();
-
- if (total_promoted >= adjusted_promotion_limit) return true;
-
intptr_t adjusted_allocation_limit =
- old_gen_allocation_limit_ - new_space_.Capacity() / 5;
+ old_generation_allocation_limit_ - new_space_.Capacity();
- if (PromotedSpaceSizeOfObjects() >= adjusted_allocation_limit) return
true;
+ if (PromotedTotalSize() >= adjusted_allocation_limit) return true;
return false;
}
-
void UpdateNewSpaceReferencesInExternalStringTable(
ExternalStringTableUpdaterCallback updater_func);
@@ -1992,13 +1968,9 @@ class Heap {
// Limit that triggers a global GC on the next (normally caused) GC.
This
// is checked when we have already decided to do a GC to help determine
- // which collector to invoke.
- intptr_t old_gen_promotion_limit_;
-
- // Limit that triggers a global GC as soon as is reasonable. This is
- // checked before expanding a paged space in the old generation and on
- // every allocation in large object space.
- intptr_t old_gen_allocation_limit_;
+ // which collector to invoke, before expanding a paged space in the old
+ // generation and on every allocation in large object space.
+ intptr_t old_generation_allocation_limit_;
// Used to adjust the limits that control the timing of the next GC.
intptr_t size_of_old_gen_at_last_old_space_gc_;
@@ -2016,7 +1988,7 @@ class Heap {
// Indicates that an allocation has failed in the old generation since
the
// last GC.
- int old_gen_exhausted_;
+ bool old_gen_exhausted_;
Object* native_contexts_list_;
--
--
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