Revert of [heap] Switch to 500k pages (patchset #5 id:80001 of https:…

…//codereview.chromium.org/2314803002/ )

Reason for revert:
Breaks arm64 nosnap debug:
https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20nosnap%20-%20debug/builds/2178

Original issue's description:
> [heap] Switch to 500k pages
>
> BUG=chromium:636331
> R=ulan@chromium.org
>
> Committed: https://crrev.com/4b618dbf8ec7f0edf377b54b48bf3c852d5e235a
> Cr-Commit-Position: refs/heads/master@{#39220}

TBR=ulan@chromium.org,mlippautz@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:636331

Review-Url: https://codereview.chromium.org/2312853005
Cr-Commit-Position: refs/heads/master@{#39229}

src/base/build_config.h

@@ -208,7 +208,7 @@
 // Bump up for Power Linux due to larger (64K) page size.
 const int kPageSizeBits = 22;
 #else
-const int kPageSizeBits = 19;
+const int kPageSizeBits = 20;
 #endif
 
 #endif  // V8_BASE_BUILD_CONFIG_H_

src/globals.h

@@ -201,9 +201,7 @@ const int kExternalAllocationSoftLimit = 64 * MB;
 // memory. This also applies to new space allocation, since objects are never
 // migrated from new space to large object space. Takes double alignment into
 // account.
-//
-// Current value: Page::kAllocatableMemory (on 32-bit arch) - 512 (slack).
-const int kMaxRegularHeapObjectSize = 507136;
+const int kMaxRegularHeapObjectSize = 512 * KB - 512;
 
 STATIC_ASSERT(kPointerSize == (1 << kPointerSizeLog2));
 

src/heap/heap.cc

@@ -78,7 +78,7 @@ Heap::Heap()
       // semispace_size_ should be a power of 2 and old_generation_size_ should
       // be a multiple of Page::kPageSize.
       max_semi_space_size_(8 * (kPointerSize / 4) * MB),
-      initial_semispace_size_(MB),
+      initial_semispace_size_(Page::kPageSize),
       max_old_generation_size_(700ul * (kPointerSize / 4) * MB),
       initial_old_generation_size_(max_old_generation_size_ /
                                    kInitalOldGenerationLimitFactor),

src/heap/mark-compact.cc

@@ -600,18 +600,18 @@ void MarkCompactCollector::ComputeEvacuationHeuristics(
   // For memory reducing and optimize for memory mode we directly define both
   // constants.
   const int kTargetFragmentationPercentForReduceMemory = 20;
-  const int kMaxEvacuatedBytesForReduceMemory = 12 * MB;
+  const int kMaxEvacuatedBytesForReduceMemory = 12 * Page::kPageSize;
   const int kTargetFragmentationPercentForOptimizeMemory = 20;
   const int kMaxEvacuatedBytesForOptimizeMemory = 6 * MB;
 
   // For regular mode (which is latency critical) we define less aggressive
   // defaults to start and switch to a trace-based (using compaction speed)
   // approach as soon as we have enough samples.
   const int kTargetFragmentationPercent = 70;
-  const int kMaxEvacuatedBytes = 4 * MB;
+  const int kMaxEvacuatedBytes = 4 * Page::kPageSize;
   // Time to take for a single area (=payload of page). Used as soon as there
   // exist enough compaction speed samples.
-  const float kTargetMsPerArea = .5;
+  const int kTargetMsPerArea = 1;
 
   if (heap()->ShouldReduceMemory()) {
     *target_fragmentation_percent = kTargetFragmentationPercentForReduceMemory;
@@ -3226,7 +3226,7 @@ int MarkCompactCollector::NumberOfParallelCompactionTasks(int pages,
   // The number of parallel compaction tasks is limited by:
   // - #evacuation pages
   // - (#cores - 1)
-  const double kTargetCompactionTimeInMs = .5;
+  const double kTargetCompactionTimeInMs = 1;
   const int kNumSweepingTasks = 3;
 
   double compaction_speed =

src/heap/spaces.h

@@ -696,8 +696,7 @@ class MemoryChunk {
 
 DEFINE_OPERATORS_FOR_FLAGS(MemoryChunk::Flags)
 
-static_assert(kMaxRegularHeapObjectSize <= MemoryChunk::kAllocatableMemory,
-              "kMaxRegularHeapObjectSize <= MemoryChunk::kAllocatableMemory");
+STATIC_ASSERT(kMaxRegularHeapObjectSize < MemoryChunk::kAllocatableMemory);
 
 // -----------------------------------------------------------------------------
 // A page is a memory chunk of a size 1MB. Large object pages may be larger.

test/cctest/heap/test-heap.cc

@@ -2369,9 +2369,6 @@ static void FillUpNewSpace(NewSpace* new_space) {
 
 
 TEST(GrowAndShrinkNewSpace) {
-  // Avoid shrinking new space in GC epilogue. This can happen if allocation
-  // throughput samples have been taken while executing the benchmark.
-  FLAG_predictable = true;
   CcTest::InitializeVM();
   Heap* heap = CcTest::heap();
   NewSpace* new_space = heap->new_space();
@@ -3617,9 +3614,6 @@ TEST(ReleaseOverReservedPages) {
   i::FLAG_page_promotion = false;
   CcTest::InitializeVM();
   Isolate* isolate = CcTest::i_isolate();
-  // If there's snapshot available, we don't know whether 20 small arrays will
-  // fit on the initial pages.
-  if (!isolate->snapshot_available()) return;
   Factory* factory = isolate->factory();
   Heap* heap = isolate->heap();
   v8::HandleScope scope(CcTest::isolate());

test/cctest/heap/test-mark-compact.cc

@@ -96,9 +96,6 @@ TEST(Promotion) {
 }
 
 HEAP_TEST(NoPromotion) {
-  // Page promotion allows pages to be moved to old space even in the case of
-  // OOM scenarios.
-  FLAG_page_promotion = false;
   CcTest::InitializeVM();
   Isolate* isolate = CcTest::i_isolate();
   {