Align ashmem region sizes to page size after ashmem creation failed.

base/memory/discardable_memory_android.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/memory/discardable_memory_android.h"
 
 #include <sys/mman.h>
 #include <unistd.h>
 
 #include <limits>
@@ skipping 19 matching lines @@
                   GetOptimalAshmemRegionSizeForAllocator()) {
   }
 
   internal::DiscardableMemoryAllocator allocator;
 
  private:
   // Returns 64 MBytes for a 512 MBytes device, 128 MBytes for 1024 MBytes...
   static size_t GetOptimalAshmemRegionSizeForAllocator() {
     // Note that this may do some I/O (without hitting the disk though) so it
     // should not be called on the critical path.
-    return internal::AlignToNextPage(
-        base::android::SysUtils::AmountOfPhysicalMemoryKB() * 1024 / 8);
+    return base::android::SysUtils::AmountOfPhysicalMemoryKB() * 1024 / 8;
   }
 };
 
 LazyInstance<DiscardableMemoryAllocatorWrapper>::Leaky g_context =
     LAZY_INSTANCE_INITIALIZER;
 
 }  // namespace
 
 namespace internal {
 
-size_t AlignToNextPage(size_t size) {
-  const size_t kPageSize = 4096;
-  DCHECK_EQ(static_cast<int>(kPageSize), getpagesize());
-  if (size > std::numeric_limits<size_t>::max() - kPageSize + 1)
-    return 0;
-  const size_t mask = ~(kPageSize - 1);
-  return (size + kPageSize - 1) & mask;
-}
-
 bool CreateAshmemRegion(const char* name,
                         size_t size,
                         int* out_fd,
                         void** out_address) {
   int fd = ashmem_create_region(name, size);
   if (fd < 0) {
     DLOG(ERROR) << "ashmem_create_region() failed";
     return false;
   }
   file_util::ScopedFD fd_closer(&fd);
@@ skipping 98 matching lines @@
 bool DiscardableMemory::PurgeForTestingSupported() {
   return false;
 }
 
 // static
 void DiscardableMemory::PurgeForTesting() {
   NOTIMPLEMENTED();
 }
 
 }  // namespace base