1 files changed, 24 insertions, 0 deletions
diff --git a/runtime/gc/space/dlmalloc_space.cc b/runtime/gc/space/dlmalloc_space.cc
index 5123e4787d..456d1b31e2 100644
--- a/runtime/gc/space/dlmalloc_space.cc
+++ b/runtime/gc/space/dlmalloc_space.cc
@@ -304,6 +304,30 @@ void DlMallocSpace::CheckMoreCoreForPrecondition() {
 }
 #endif
 
+static void MSpaceChunkCallback(void* start, void* end, size_t used_bytes, void* arg) {
+  size_t chunk_size = reinterpret_cast<uint8_t*>(end) - reinterpret_cast<uint8_t*>(start);
+  if (used_bytes < chunk_size) {
+    size_t chunk_free_bytes = chunk_size - used_bytes;
+    size_t& max_contiguous_allocation = *reinterpret_cast<size_t*>(arg);
+    max_contiguous_allocation = std::max(max_contiguous_allocation, chunk_free_bytes);
+  }
+}
+
+void DlMallocSpace::LogFragmentationAllocFailure(std::ostream& os, size_t failed_alloc_bytes) {
+  Thread* self = Thread::Current();
+  size_t max_contiguous_allocation = 0;
+  // To allow the Walk/InspectAll() to exclusively-lock the mutator
+  // lock, temporarily release the shared access to the mutator
+  // lock here by transitioning to the suspended state.
+  Locks::mutator_lock_->AssertSharedHeld(self);
+  self->TransitionFromRunnableToSuspended(kSuspended);
+  Walk(MSpaceChunkCallback, &max_contiguous_allocation);
+  self->TransitionFromSuspendedToRunnable();
+  Locks::mutator_lock_->AssertSharedHeld(self);
+  os << "; failed due to fragmentation (largest possible contiguous allocation "
+     <<  max_contiguous_allocation << " bytes)";
+}
+
 }  // namespace space
 }  // namespace gc
 }  // namespace art