[Heap] Fix ArrayBuffer_SemiSpaceCopyMultipleTasks to respect PPC page size

test/cctest/heap/test-array-buffer-tracker.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/heap/array-buffer-tracker.h"
 #include "test/cctest/cctest.h"
 #include "test/cctest/heap/heap-utils.h"
 
 namespace {
 
@@ skipping 274 matching lines @@
     heap::GcAndSweep(heap, OLD_SPACE);
     CHECK(IsTracked(JSArrayBuffer::cast(root->get(0))));
   }
 }
 
 UNINITIALIZED_TEST(ArrayBuffer_SemiSpaceCopyMultipleTasks) {
   if (FLAG_optimize_for_size) return;
   // Test allocates JSArrayBuffer on different pages before triggering a
   // full GC that performs the semispace copy. If parallelized, this test
   // ensures proper synchronization in TSAN configurations.
-  FLAG_min_semi_space_size = 2;
+  FLAG_min_semi_space_size = 2 * Page::kPageSize / MB;
   v8::Isolate::CreateParams create_params;
   create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
   v8::Isolate* isolate = v8::Isolate::New(create_params);
   i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
   {
     v8::Isolate::Scope isolate_scope(isolate);
     v8::HandleScope handle_scope(isolate);
     v8::Context::New(isolate)->Enter();
     Heap* heap = i_isolate->heap();
 
     Local<v8::ArrayBuffer> ab1 = v8::ArrayBuffer::New(isolate, 100);
     Handle<JSArrayBuffer> buf1 = v8::Utils::OpenHandle(*ab1);
     heap::FillCurrentPage(heap->new_space());
     Local<v8::ArrayBuffer> ab2 = v8::ArrayBuffer::New(isolate, 100);
     Handle<JSArrayBuffer> buf2 = v8::Utils::OpenHandle(*ab2);
     CHECK_NE(Page::FromAddress(buf1->address()),
              Page::FromAddress(buf2->address()));
     heap::GcAndSweep(heap, OLD_SPACE);
   }
 }
 
 }  // namespace internal
 }  // namespace v8