[nirvdrum]

On macOS, RSS is measured via Fiddle and loading it the way ruby-bench does (force-activation) via Bundler, loads code that redefines methods like == and hash, leading to cache invalidation that adversely affects benchmark runs.

[XrXr]

Nice catch.
If it has to be be in use_gemfile, fine, but is it possible to simplify the loading processing by lifting the

    @fn = begin
      load_fiddle
      Fiddle::Function.new(
        Fiddle.dlopen(nil)['proc_pid_rusage'],
        [Fiddle::TYPE_INT, Fiddle::TYPE_INT, Fiddle::TYPE_VOIDP],
        Fiddle::TYPE_INT,
      )
    rescue LoadError, Fiddle::DLError, NameError
      nil
    end

out into module ProcPidUsage scope? (Or call it if macos.) Generally memoization is not a great pattern for stability.

[tekknolagi]

+1 just eager load it who cares

[tekknolagi]

lgtm