--- old/src/os/posix/vm/os_posix.cpp	2012-12-13 11:24:53.000000000 +0100
+++ new/src/os/posix/vm/os_posix.cpp	2012-12-13 11:24:53.000000000 +0100
@@ -93,6 +93,39 @@
   return;
 }
 
+char* os::reserve_memory_aligned(size_t bytes, size_t alignment) {
+  size_t size = align_size_up(bytes, alignment);
+  size_t extra_size = size + alignment;
+  char* extra_base = os::reserve_memory(extra_size, NULL, alignment);
+
+  if (extra_base == NULL) {
+    return NULL;
+  }
+
+  // Do manual alignment
+  char* aligned_base = (char*) align_size_up((uintptr_t) extra_base, alignment);
+
+  // [  |                                       |  ]
+  // ^ extra_base
+  //    ^ extra_base + begin_offset == aligned_base
+  //     extra_base + begin_offset + size       ^
+  //                       extra_base + extra_size ^
+  // |<>| == begin_offset
+  //                              end_offset == |<>|
+  size_t begin_offset = aligned_base - extra_base;
+  size_t end_offset = (extra_base + extra_size) - (aligned_base + size);
+
+  if (begin_offset > 0) {
+      os::release_memory(extra_base, begin_offset);
+  }
+
+  if (end_offset > 0) {
+      os::release_memory(extra_base + begin_offset + size, end_offset);
+  }
+
+  return aligned_base;
+}
+
 void os::Posix::print_load_average(outputStream* st) {
   st->print("load average:");
   double loadavg[3];