snmalloc: A Message Passing Allocator

Paul LiƩtar, Theodore Butler, Sylvan Clebsch, Sophia Drossopoulou, Juliana Franco, Matthew J. Parkinson, Alex Shamis, Christoph M. Wintersteiger, David Chisnall
Published in 2019 ACM SIGPLAN International Symposium on Memory Management (ISMM), 2019

Snmalloc is an implementation of malloc aimed at workloads in which objects are typically deallocated by a different thread than the one that had allocated them. We use the term producer/consumer for such workloads. Snmalloc uses a novel message passing scheme which returns deallocated objects to the originating allocator in batches without taking any locks. It also uses a novel bump pointer-free list data structure with which just 64-bits of meta-data are sufficient for each 64 KiB slab. On such producer/consumer benchmarks our approach performs better than existing allocators.

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