[tracing] Fix resident size of malloc dump provider when tcmalloc is used

base/trace_event/malloc_dump_provider.cc

Index: base/trace_event/malloc_dump_provider.cc
diff --git a/base/trace_event/malloc_dump_provider.cc b/base/trace_event/malloc_dump_provider.cc
index 28aa140d6702bb61c55dab49ae3be6c196078b94..acbe21130e66b9a6f778d09765010183822dc419 100644
--- a/base/trace_event/malloc_dump_provider.cc
+++ b/base/trace_event/malloc_dump_provider.cc
@@ -8,6 +8,10 @@
 
 #include "base/trace_event/process_memory_dump.h"

[Primiano Tucci (use gerrit), 2015/10/26 14:25:35]

please add an include "build/build_config.h", otherwise you might end up never
seeing the USE_TCMALLOC define

[ssid, 2015/10/26 17:10:40]

Done.

 
+#if defined(USE_TCMALLOC)
+#include "third_party/tcmalloc/chromium/src/gperftools/malloc_extension.h"
+#endif
+
 namespace base {
 namespace trace_event {
 
@@ -30,23 +34,50 @@ MallocDumpProvider::~MallocDumpProvider() {
 // the current process.
 bool MallocDumpProvider::OnMemoryDump(const MemoryDumpArgs& args,
                                       ProcessMemoryDump* pmd) {
+  size_t total_virtual_size = 0;
+  size_t resident_size = 0;
+  size_t allocated_objects_size = 0;
+
+#if defined(USE_TCMALLOC)
+  size_t pageheap_unmapped_bytes = 0;
+  bool res = MallocExtension::instance()->GetNumericProperty(
+      "generic.heap_size", &total_virtual_size);
+  DCHECK(res);
+  res = MallocExtension::instance()->GetNumericProperty(
+      "tcmalloc.pageheap_unmapped_bytes", &pageheap_unmapped_bytes);
+  DCHECK(res);
+  res = MallocExtension::instance()->GetNumericProperty(
+      "generic.current_allocated_bytes", &allocated_objects_size);
+  DCHECK(res);
+
+  // TODO(ssid): Usage of metadata is not included in page heap bytes
+  // (crbug.com/546491). MallocExtension::GetNumericProperty will be extended
+  // to get this value.
+  resident_size = total_virtual_size - pageheap_unmapped_bytes;

[Primiano Tucci (use gerrit), 2015/10/26 14:25:35]

Maybe add a comment with a pointer to the tcmalloc dump code that explains how
did you choose to do this math.

[ssid, 2015/10/26 17:10:40]

Done.

+#else   // defined(USE_TCMALLOC)
+
   struct mallinfo info = mallinfo();
   DCHECK_GE(info.arena + info.hblkhd, info.uordblks);
 
-  // When the system allocator is implemented by tcmalloc, the total heap
-  // size is given by |arena| and |hblkhd| is 0. In case of Android's jemalloc
-  // |arena| is 0 and the outer pages size is reported by |hblkhd|. In case of
-  // dlmalloc the total is given by |arena| + |hblkhd|.
-  // For more details see link: http://goo.gl/fMR8lF.
+  // In case of Android's jemalloc |arena| is 0 and the outer pages size is
+  // reported by |hblkhd|. In case of dlmalloc the total is given by
+  // |arena| + |hblkhd|. For more details see link: http://goo.gl/fMR8lF.
+  total_virtual_size = info.arena + info.hblkhd;
+  resident_size = info.uordblks;
+  allocated_objects_size = info.uordblks;
+#endif  // defined(USE_TCMALLOC)
+
   MemoryAllocatorDump* outer_dump = pmd->CreateAllocatorDump("malloc");
-  outer_dump->AddScalar("virtual_size",
-                        MemoryAllocatorDump::kUnitsBytes,
-                        info.arena + info.hblkhd);
+  outer_dump->AddScalar("virtual_size", MemoryAllocatorDump::kUnitsBytes,
+                        total_virtual_size);
+  outer_dump->AddScalar(MemoryAllocatorDump::kNameSize,
+                        MemoryAllocatorDump::kUnitsBytes, resident_size);
 
   // Total allocated space is given by |uordblks|.
   MemoryAllocatorDump* inner_dump = pmd->CreateAllocatorDump(kAllocatedObjects);
   inner_dump->AddScalar(MemoryAllocatorDump::kNameSize,
-                        MemoryAllocatorDump::kUnitsBytes, info.uordblks);
+                        MemoryAllocatorDump::kUnitsBytes,
+                        allocated_objects_size);
 
   return true;
 }