Author: llunak Date: Fri Oct 11 12:34:39 2019 New Revision: 374583 URL: http://llvm.org/viewvc/llvm-project?rev=374583&view=rev Log: make ConstString allocate memory in non-tiny chunks
BumpPtrAllocator allocates in 4KiB chunks, which with any larger project is going to result in a large number of allocations. Increasing allocation size this way can save 10%-20% of symbol load time for a huge C++ project with correctly built debuginfo. Differential Revision: https://reviews.llvm.org/D68549 Modified: lldb/trunk/source/Utility/ConstString.cpp Modified: lldb/trunk/source/Utility/ConstString.cpp URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Utility/ConstString.cpp?rev=374583&r1=374582&r2=374583&view=diff ============================================================================== --- lldb/trunk/source/Utility/ConstString.cpp (original) +++ lldb/trunk/source/Utility/ConstString.cpp Fri Oct 11 12:34:39 2019 @@ -31,7 +31,10 @@ using namespace lldb_private; class Pool { public: typedef const char *StringPoolValueType; - typedef llvm::StringMap<StringPoolValueType, llvm::BumpPtrAllocator> + // BumpPtrAllocator allocates in 4KiB chunks, any larger C++ project is going + // to have megabytes of symbols, so allocate in larger chunks. + typedef llvm::BumpPtrAllocatorImpl<llvm::MallocAllocator, 1048576> Allocator; + typedef llvm::StringMap<StringPoolValueType, Allocator> StringPool; typedef llvm::StringMapEntry<StringPoolValueType> StringPoolEntryType; @@ -152,7 +155,9 @@ protected: struct PoolEntry { mutable llvm::sys::SmartRWMutex<false> m_mutex; - StringPool m_string_map; + // StringMap by default starts with 16 buckets, any larger project is + // going to have many symbols, so start with a larger value. + StringPool m_string_map = StringPool( 65536 ); }; std::array<PoolEntry, 256> m_string_pools; _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
