1 files changed, 23 insertions, 11 deletions
diff --git a/base/memory/discardable_memory_allocator_android.cc b/base/memory/discardable_memory_allocator_android.cc
index 5e10817..a0a3aff 100644
--- a/base/memory/discardable_memory_allocator_android.cc
+++ b/base/memory/discardable_memory_allocator_android.cc
@@ -44,6 +44,8 @@ namespace {
 // issues.
 const size_t kMaxChunkFragmentationBytes = 4096 - 1;
 
+const size_t kMinAshmemRegionSize = 32 * 1024 * 1024;
+
 }  // namespace
 
 namespace internal {
@@ -104,6 +106,7 @@ class DiscardableMemoryAllocator::AshmemRegion {
       size_t size,
       const std::string& name,
       DiscardableMemoryAllocator* allocator) {
+    DCHECK_EQ(size, internal::AlignToNextPage(size));
     int fd;
     void* base;
     if (!internal::CreateAshmemRegion(name.c_str(), size, &fd, &base))
@@ -364,8 +367,12 @@ DiscardableMemoryAllocator::DiscardableAshmemChunk::~DiscardableAshmemChunk() {
   ashmem_region_->OnChunkDeletion(address_, size_);
 }
 
-DiscardableMemoryAllocator::DiscardableMemoryAllocator(const std::string& name)
-    : name_(name) {
+DiscardableMemoryAllocator::DiscardableMemoryAllocator(
+    const std::string& name,
+    size_t ashmem_region_size)
+    : name_(name),
+      ashmem_region_size_(std::max(kMinAshmemRegionSize, ashmem_region_size)) {
+  DCHECK_GE(ashmem_region_size_, kMinAshmemRegionSize);
 }
 
 DiscardableMemoryAllocator::~DiscardableMemoryAllocator() {
@@ -389,16 +396,21 @@ scoped_ptr<DiscardableMemory> DiscardableMemoryAllocator::Allocate(
     if (memory)
       return memory.Pass();
   }
-  scoped_ptr<AshmemRegion> new_region(
-      AshmemRegion::Create(
-          std::max(static_cast<size_t>(kMinAshmemRegionSize), aligned_size),
-          name_.c_str(), this));
-  if (!new_region) {
-    // TODO(pliard): consider adding an histogram to see how often this happens.
-    return scoped_ptr<DiscardableMemory>();
+  // The creation of the (large) ashmem region might fail if the address space
+  // is too fragmented. In case creation fails the allocator retries by
+  // repetitively dividing the size by 2.
+  const size_t min_region_size = std::max(kMinAshmemRegionSize, aligned_size);
+  for (size_t region_size = std::max(ashmem_region_size_, aligned_size);
+       region_size >= min_region_size; region_size /= 2) {
+    scoped_ptr<AshmemRegion> new_region(
+        AshmemRegion::Create(region_size, name_.c_str(), this));
+    if (!new_region)
+      continue;
+    ashmem_regions_.push_back(new_region.release());
+    return ashmem_regions_.back()->Allocate_Locked(size, aligned_size);
   }
-  ashmem_regions_.push_back(new_region.release());
-  return ashmem_regions_.back()->Allocate_Locked(size, aligned_size);
+  // TODO(pliard): consider adding an histogram to see how often this happens.
+  return scoped_ptr<DiscardableMemory>();
 }
 
 void DiscardableMemoryAllocator::DeleteAshmemRegion_Locked(