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 499 matching lines @@
   // 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();
     // Check that the initial heap is also below the limit.
+// In PPC the page size is 64K, hence no memory will be freed causing
+// the initial committed memory in code spaces to be exactly 2M.
+// changing the test case to accomodate this.
+#if V8_OS_LINUX && V8_HOST_ARCH_PPC
+    CHECK_LE(heap->paged_space(i)->CommittedMemory(), kMaxInitialSizePerSpace);

[Michael Lippautz, 2016/11/25 15:23:51]

I would put the #define_s around kMaxInitialSizePerSpace above and just make it
slightly larger. This constant is arbitrary and should just help us in
recognizing any regressions.

Also, there's no memory being freed here as we do these checks right after
deserialization. So I would write something along the lines of "For 64k pages we
have more fragmentation and need a larger limit."

+#else
     CHECK_LT(heap->paged_space(i)->CommittedMemory(), kMaxInitialSizePerSpace);
+#endif
   }
 
   // Executing the empty script gets by with the same number of pages, i.e.,
   // requires no extra space.
   CompileRun("/*empty*/");
   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;
     CHECK_EQ(page_count[i], isolate->heap()->paged_space(i)->CountTotalPages());
   }
@@ skipping 261 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