Index: third_party/tcmalloc/chromium/src/common.cc |
diff --git a/third_party/tcmalloc/chromium/src/common.cc b/third_party/tcmalloc/chromium/src/common.cc |
index dd175f223692a5adb37048140b30422bae79fe40..30eaa2e85e545f7afdc6857b8c67f6b029dd1df9 100644 |
--- a/third_party/tcmalloc/chromium/src/common.cc |
+++ b/third_party/tcmalloc/chromium/src/common.cc |
@@ -58,9 +58,9 @@ static inline int LgFloor(size_t n) { |
int AlignmentForSize(size_t size) { |
int alignment = kAlignment; |
- if (size > kMaxSize) { |
- // Cap alignment at kPageSize for large sizes. |
- alignment = kPageSize; |
+ if (size >= 2048) { |
+ // Cap alignment at 256 for large sizes. |
+ alignment = 256; |
} else if (size >= 128) { |
// Space wasted due to alignment is at most 1/8, i.e., 12.5%. |
alignment = (1 << LgFloor(size)) / 8; |
@@ -69,10 +69,6 @@ int AlignmentForSize(size_t size) { |
// requirements for some SSE types. |
alignment = 16; |
} |
- // Maximum alignment allowed is page size alignment. |
- if (alignment > kPageSize) { |
- alignment = kPageSize; |
- } |
CHECK_CONDITION(size < 16 || alignment >= 16); |
CHECK_CONDITION((alignment & (alignment - 1)) == 0); |
return alignment; |
@@ -115,23 +111,22 @@ void SizeMap::Init() { |
int sc = 1; // Next size class to assign |
int alignment = kAlignment; |
CHECK_CONDITION(kAlignment <= 16); |
+ int last_lg = -1; |
for (size_t size = kMinClassSize; size <= kMaxSize; size += alignment) { |
- alignment = AlignmentForSize(size); |
+ int lg = LgFloor(size); |
+ if (lg > last_lg) { |
+ // Increase alignment every so often to reduce number of size classes. |
+ alignment = AlignmentForSize(size); |
+ last_lg = lg; |
+ } |
CHECK_CONDITION((size % alignment) == 0); |
- int blocks_to_move = NumMoveSize(size) / 4; |
- size_t psize = 0; |
- do { |
+ // Allocate enough pages so leftover is less than 1/8 of total. |
+ // This bounds wasted space to at most 12.5%. |
+ size_t psize = kPageSize; |
+ while ((psize % size) > (psize >> 3)) { |
psize += kPageSize; |
- // Allocate enough pages so leftover is less than 1/8 of total. |
- // This bounds wasted space to at most 12.5%. |
- while ((psize % size) > (psize >> 3)) { |
- psize += kPageSize; |
- } |
- // Continue to add pages until there are at least as many objects in |
- // the span as are needed when moving objects from the central |
- // freelists and spans to the thread caches. |
- } while ((psize / size) < (blocks_to_move)); |
+ } |
const size_t my_pages = psize >> kPageShift; |
if (sc > 1 && my_pages == class_to_pages_[sc-1]) { |