diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.cpp --- a/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.cpp +++ b/compiler-rt/lib/sanitizer_common/sanitizer_stackdepot.cpp @@ -25,12 +25,9 @@ using hash_type = u64; hash_type stack_hash; u32 link; - atomic_uint32_t tag_and_use_count; // tag : 12 high bits; use_count : 20; + u32 tag; static const u32 kTabSizeLog = SANITIZER_ANDROID ? 16 : 20; - static const u32 kUseCountBits = 20; - static const u32 kMaxUseCount = 1 << kUseCountBits; - static const u32 kUseCountMask = (1 << kUseCountBits) - 1; typedef StackTrace args_type; bool eq(hash_type hash, const args_type &args) const { @@ -53,19 +50,6 @@ typedef StackDepotHandle handle_type; }; -COMPILER_CHECK(StackDepotNode::kMaxUseCount >= (u32)kStackDepotMaxUseCount); - -int StackDepotHandle::use_count() const { - return atomic_load(&node_->tag_and_use_count, memory_order_relaxed) & - StackDepotNode::kUseCountMask; -} -void StackDepotHandle::inc_use_count_unsafe() { - u32 prev = - atomic_fetch_add(&node_->tag_and_use_count, 1, memory_order_relaxed) & - StackDepotNode::kUseCountMask; - CHECK_LT(prev + 1, StackDepotNode::kMaxUseCount); -} - // FIXME(dvyukov): this single reserved bit is used in TSan. typedef StackDepotBase StackDepot; @@ -74,11 +58,22 @@ // caching efficiency. static TwoLevelMap tracePtrs; +// Keep mutable data out of frequently access nodes to improve caching +// efficiency. +static TwoLevelMap + useCounts; + +int StackDepotHandle::use_count() const { + return atomic_load_relaxed(&useCounts[id_]); +} + +void StackDepotHandle::inc_use_count_unsafe() { + atomic_fetch_add(&useCounts[id_], 1, memory_order_relaxed); +} void StackDepotNode::store(u32 id, const args_type &args, hash_type hash) { - CHECK_EQ(args.tag & (~kUseCountMask >> kUseCountBits), args.tag); - atomic_store(&tag_and_use_count, args.tag << kUseCountBits, - memory_order_relaxed); + tag = args.tag; stack_hash = hash; uptr *stack_trace = traceAllocator.alloc(args.size + 1); *stack_trace = args.size; @@ -90,8 +85,6 @@ const uptr *stack_trace = tracePtrs[id]; if (!stack_trace) return {}; - u32 tag = - atomic_load(&tag_and_use_count, memory_order_relaxed) >> kUseCountBits; return args_type(stack_trace + 1, *stack_trace, tag); }