Original C++ lab with docs and maybe video
Rust version is Linux only so far. The C++ original also supports macOS and Windows. Contributions welcome!
Observe the memory bottleneck:
- Build benchmark binary:
cargo bench --no-run. It should print path to the binary. - Confirm we're loading a lot from main memory:
perf stat -e cache-references,LLC-loads,LLC-load-misses <binary>. I get over 50% Last Level Cache (L3) misses, meaning those loads had to go to main memory. - Check TLB:
perf stat -e dTLB-loads,dTLB-load-misses <binary>. I have about 12% TLB misses (before optimization).
Optimize:
Enable huge pages on Linux (128 pages is a guess, try other numbers): sudo bash -c 'echo 128 > /proc/sys/vm/nr_hugepages'. If you use anonymous mmaped pages I don't think you need to mount a hugetlbfs filesystem like the docs recommend.
I got a ~30% speedup.