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The memory allocator plays a key role in the performance of applications, but none of the existing profilers can pinpoint performance slowdowns caused by a memory allocator. Consequently, programmers may spend time improving application code incorrectly or unnecessarily, achieving low or no performance improvement. This paper designs the first profiler—MemPerf—to identify allocator-induced performance slowdowns without comparing against another allocator. Based on the key observation that an allocator may impact the whole life-cycle of heap objects, including the accesses (or uses) of these objects, MemPerf proposes a life-cycle based detection to identify slowdowns caused by slow memory management operations and slow accesses separately. For the prior one, MemPerf proposes a thread-aware and type-aware performance modeling to identify slow management operations. For slow memory accesses, MemPerf utilizes a top-down approach to identify all possible reasons for slow memory accesses introduced by the allocator, mainly due to cache and TLB misses, and further proposes a unified method to identify them correctly and efficiently. Based on our extensive evaluation, MemPerf reports 98% medium and large allocator-reduced slowdowns (larger than 5%) correctly without reporting any false positives. MemPerf also pinpoints multiple known and unknown design issues in widely-used allocators. 

The NUMA architecture accommodates the hardware trend of an increasing number of CPU cores. It requires the coop- eration of memory allocators to achieve good performance for multithreaded applications. Unfortunately, existing allo- cators do not support NUMA architecture well. This paper presents a novel memory allocator – NUMAlloc , that is de- signed for the NUMA architecture. NUMAlloc is centered on a binding-based memory management. On top of it, NUMAl- loc proposes an “origin-aware memory management” to ensure the locality of memory allocations and deallocations, as well as a method called “incremental sharing” to balance the performance benefits and memory overhead of using transparent huge pages. According to our extensive evalua- tion, NUMAlloc hasthebestperformanceamongallevaluated allocators, running 15.7% faster than the second-best allo- cator (mimalloc), and 20.9% faster than the default Linux allocator with reasonable memory overhead. NUMAlloc is also scalable to 128 threads and is ready for deployment.