Changeset 28727 in webkit for trunk/JavaScriptCore/wtf/TCSystemAlloc.cpp

Timestamp:

Dec 14, 2007, 4:25:45 PM (18 years ago)

Author:

[email protected]

Message:

Add logic for TCMalloc to release memory to the system

Reviewed by Maciej and Oliver.

Add final changes to make TCMalloc release memory to the system.
This results in a 0.4% regression against ToT, but this is offset
against the gains made by the original TCMalloc r38 merge - in fact
we retain around 0.3-0.4% progression overall.

File:

• trunk/JavaScriptCore/wtf/TCSystemAlloc.cpp (modified) (2 diffs)

trunk/JavaScriptCore/wtf/TCSystemAlloc.cpp

@@ -381 +381 @@
 }
 
-#ifndef MADV_DONTNEED
-void TCMalloc_SystemRelease(void*, size_t) {}
-#else
 void TCMalloc_SystemRelease(void* start, size_t length) {
+#ifdef MADV_DONTNEED
   if (FLAGS_malloc_devmem_start) {
     // It's not safe to use MADV_DONTNEED if we've been mapping
@@ -416 +414 @@
     }
   }
-}
-#endif
+#endif
+
+#if HAVE(MMAP)
+  void *newAddress = mmap(start, length, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, -1, 0);
+  UNUSED_PARAM(newAddress);
+  // If the mmap failed then that's ok, we just won't return the memory to the system.
+  ASSERT(newAddress == start || newAddress == reinterpret_cast<void*>(MAP_FAILED));
+#endif
+}