Tailslayer: C++ Library for Reducing RAM Tail Latency from DRAM Refresh Stalls

Tailslayer is a C++ library that reduces tail latency in RAM reads caused by DRAM refresh stalls.

It replicates data across multiple, independent DRAM channels with uncorrelated refresh schedules, using (undocumented!) channel scrambling offsets that works on AMD, Intel, and Graviton.

Once the request comes in, Tailslayer issues hedged reads across all replicas, allowing the work to be performed on whichever result responds first.

The library code is available in hedged_reader.cpp and the example using the library can be found in tailslayer_example.cpp.