PPC64: Changing test-spaces/SizeOfInitialHeap to accomodate 64K page size

test/cctest/heap/test-spaces.cc

 // Copyright 2011 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 485 matching lines @@
   // Skip this test on the custom snapshot builder.
   if (!CcTest::global()
            ->Get(context, v8_str("assertEquals"))
            .ToLocalChecked()
            ->IsUndefined()) {
     return;
   }
   // Initial size of LO_SPACE
   size_t initial_lo_space = isolate->heap()->lo_space()->Size();
 
-  // The limit for each space for an empty isolate containing just the
-  // snapshot.
+// The limit for each space for an empty isolate containing just the
+// snapshot.
+// In PPC the page size is 64K, causing more internal fragmentation
+// hence requiring a larger limit.
+#if V8_OS_LINUX && V8_HOST_ARCH_PPC
+  const size_t kMaxInitialSizePerSpace = 3 * MB;
+#else
   const size_t kMaxInitialSizePerSpace = 2 * MB;
+#endif
 
   // Freshly initialized VM gets by with the snapshot size (which is below
   // kMaxInitialSizePerSpace per space).
   Heap* heap = isolate->heap();
   int page_count[LAST_PAGED_SPACE + 1] = {0, 0, 0, 0};
   for (int i = FIRST_PAGED_SPACE; i <= LAST_PAGED_SPACE; i++) {
     // Debug code can be very large, so skip CODE_SPACE if we are generating it.
     if (i == CODE_SPACE && i::FLAG_debug_code) continue;
 
     page_count[i] = heap->paged_space(i)->CountTotalPages();
@@ skipping 273 matching lines @@
   HeapObject* filler =
       HeapObject::FromAddress(array->address() + array->Size());
   CHECK_EQ(filler->map(), CcTest::heap()->two_pointer_filler_map());
 
   const size_t shrinked = page->ShrinkToHighWaterMark();
   CHECK_EQ(0u, shrinked);
 }
 
 }  // namespace internal
 }  // namespace v8