Record YJIT stats in MPLR harness

Author: maximecb

harness/harness-common.rb

@@ -53,20 +53,24 @@ def get_rss
 YB_OUTPUT_FILE = File.expand_path yb_env_var
 
 def return_results(times)
+  yjit_bench_results = {
+    "RUBY_DESCRIPTION" => RUBY_DESCRIPTION,
+    "values" => times,
+  }
+
   # Collect our own peak mem usage as soon as reasonable after finishing the last iteration.
   peak_mem_bytes = get_rss
   puts "RSS: %.1fMiB" % (peak_mem_bytes / 1024.0 / 1024.0)
+  yjit_bench_results["rss"] = peak_mem_bytes
+
+  if defined?(RubyVM::YJIT) && RubyVM::YJIT.stats_enabled?
+    yjit_bench_results["yjit_stats"] = RubyVM::YJIT.runtime_stats
+  end
 
   require "json"
   out_path = YB_OUTPUT_FILE
   system('mkdir', '-p', File.dirname(out_path))
 
-  yjit_bench_results = {
-    "RUBY_DESCRIPTION" => RUBY_DESCRIPTION,
-    "values" => times,
-    "rss" => peak_mem_bytes
-  }
-
   # Using default path? Print where we put it.
   puts "Writing file #{out_path}" unless ENV["RESULT_JSON_PATH"]