From: Martin Pieuchot <mpi@grenadille.net>
Subject: Re: [PATCH] convert mpl ticket lock to anderson's lock
To: Mateusz Guzik <mjguzik@gmail.com>
Cc: tech@openbsd.org
Date: Tue, 17 Feb 2026 09:23:15 +0100

On 27/12/25(Sat) 06:24, Mateusz Guzik wrote:
> Example microbenchmark doing fstat in 8 threads (ops/s):
> before: 2305501
> after: 5891611 (+155%)
> 
> Booted with WITNESS et al, survived several kernel builds no problem.
> 
> Needs more testing of course.

Here are some numbers building a kernel and libLLVM on a amd64 i9 w/ 24
cores and an arm64 Ampere Altra w/ 80 cores.

vanilla - amd64 - kernel -j24
=============================
    0m47.40s real    10m41.77s user     4m00.12s system		(cold)
    0m48.19s real    10m59.92s user     4m00.97s system
    0m49.22s real    11m19.23s user     4m06.63s system

anderson - amd64 - kernel -j24
==============================
    0m48.01s real    10m53.56s user     4m03.85s system		(cold)
    0m49.65s real    11m26.71s user     4m07.10s system
    0m50.00s real    11m36.01s user     4m07.08s system

vanilla - arm64 - kernel -j48
=============================
    1m10.41s real    14m06.83s user    24m28.19s system		(cold)
    1m11.21s real    14m01.66s user    24m37.54s system
    1m11.37s real    14m04.17s user    24m33.37s system

anderson - arm64 - kernel -j48
==============================
    1m11.02s real    13m59.98s user    24m42.46s system		(cold)
    1m11.48s real    14m01.83s user    24m43.20s system
    1m11.54s real    14m03.91s user    24m41.63s system

vanilla - amd64 - libLLVM -j24
==============================
   11m51.87s real   240m05.22s user    34m45.38s system		(cold)
   11m55.73s real   240m17.56s user    35m47.06s system
   12m02.38s real   241m32.83s user    36m37.51s system

anderson - amd64 - libLLVM -j24
===============================
   11m56.16s real   241m59.39s user    34m52.01s system		(cold)
   11m47.98s real   237m43.06s user    35m31.95s system
   11m56.02s real   239m36.04s user    36m06.48s system

vanilla - arm64 - libLLVM -j48
==============================
   18m37.50s real   569m58.77s user   267m49.27s system
   18m44.55s real   570m28.07s user   270m17.30s system
   18m45.46s real   569m55.88s user   271m13.74s system

anderson - arm64 - libLLVM -j48
===============================
   18m22.51s real   569m20.67s user   261m34.81s system
   18m31.35s real   571m37.11s user   262m50.73s system
   18m34.12s real   569m40.94s user   266m25.65s system