Set CPU frequency governor and frequency before running the benchmarks (

#6715)
IntersectMBO · Dec 3, 2024 · 72af216 · 72af216
1 parent 916e572
commit 72af216
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Showing 2 changed files with 10 additions and 2 deletions.
diff --git a/nix/shell.nix b/nix/shell.nix
@@ -22,8 +22,12 @@ let
     '';
 
 
-  # Underlying benchmarking library used by plutus-benchmark and tasty-papi
-  papi-pkgs = lib.optional pkgs.hostPlatform.isLinux pkgs.papi;
+  papi-pkgs = lib.optionals pkgs.hostPlatform.isLinux [
+    # Needed to fix the frequency and governor of the CPU running the benchmarks
+    pkgs.cpufrequtils
+    # Underlying benchmarking library used by plutus-benchmark and tasty-papi
+    pkgs.papi
+  ];
 
 
   all-pkgs = [

diff --git a/scripts/ci-plutus-benchmark.sh b/scripts/ci-plutus-benchmark.sh
@@ -68,6 +68,10 @@ cabal clean
 if [[ -z $(which taskset) ]]; then
    TASKSET=""
 else
+   echo "[ci-plutus-benchmark]: Setting CPU $CAPABILITY_NUM frequency governor to 'userspace' and frequency to 4.21GHz"
+   # This makes the benchmark reliable on a single core and addresses the issue of large variance in the results.
+   cpufreq-set --cpu $CAPABILITY_NUM --governor userspace
+   cpufreq-set --cpu $CAPABILITY_NUM --related --freq 4.21GHz
    TASKSET="taskset -c $CAPABILITY_NUM"
 fi