Reset GPUs before power benchmark

audit/internal/platform/benchmark_test.go

@@ -1,8 +1,13 @@
 package platform
 
 import (
+	"context"
+	"os"
+	"os/exec"
+	"path/filepath"
 	"strings"
 	"testing"
+	"time"
 )
 
 func TestResolveBenchmarkProfile(t *testing.T) {
@@ -182,6 +187,75 @@ func TestBenchmarkCalibrationThrottleReasonIgnoresPowerReasons(t *testing.T) {
 	}
 }
 
+func TestResetBenchmarkGPUsSkipsWithoutRoot(t *testing.T) {
+	t.Parallel()
+
+	oldGeteuid := benchmarkGeteuid
+	oldExec := satExecCommand
+	benchmarkGeteuid = func() int { return 1000 }
+	satExecCommand = func(name string, args ...string) *exec.Cmd {
+		t.Fatalf("unexpected command: %s %v", name, args)
+		return nil
+	}
+	t.Cleanup(func() {
+		benchmarkGeteuid = oldGeteuid
+		satExecCommand = oldExec
+	})
+
+	var logs []string
+	failed := resetBenchmarkGPUs(context.Background(), filepath.Join(t.TempDir(), "verbose.log"), []int{0, 2}, func(line string) {
+		logs = append(logs, line)
+	})
+	if got, want := strings.Join(logs, "\n"), "power benchmark pre-flight: root privileges unavailable, GPU reset skipped"; !strings.Contains(got, want) {
+		t.Fatalf("logs=%q want substring %q", got, want)
+	}
+	if len(failed) != 2 || failed[0] != 0 || failed[1] != 2 {
+		t.Fatalf("failed=%v want [0 2]", failed)
+	}
+}
+
+func TestResetBenchmarkGPUsResetsEachGPU(t *testing.T) {
+	t.Parallel()
+
+	dir := t.TempDir()
+	script := filepath.Join(dir, "nvidia-smi")
+	argsLog := filepath.Join(dir, "args.log")
+	if err := os.WriteFile(script, []byte("#!/bin/sh\nprintf '%s\\n' \"$*\" >> "+argsLog+"\nprintf 'ok\\n'\n"), 0755); err != nil {
+		t.Fatalf("write script: %v", err)
+	}
+
+	oldGeteuid := benchmarkGeteuid
+	oldSleep := benchmarkSleep
+	oldLookPath := satLookPath
+	benchmarkGeteuid = func() int { return 0 }
+	benchmarkSleep = func(time.Duration) {}
+	satLookPath = func(file string) (string, error) {
+		if file == "nvidia-smi" {
+			return script, nil
+		}
+		return exec.LookPath(file)
+	}
+	t.Cleanup(func() {
+		benchmarkGeteuid = oldGeteuid
+		benchmarkSleep = oldSleep
+		satLookPath = oldLookPath
+	})
+
+	failed := resetBenchmarkGPUs(context.Background(), filepath.Join(dir, "verbose.log"), []int{2, 5}, nil)
+	if len(failed) != 0 {
+		t.Fatalf("failed=%v want no failures", failed)
+	}
+	raw, err := os.ReadFile(argsLog)
+	if err != nil {
+		t.Fatalf("read args log: %v", err)
+	}
+	got := strings.Fields(string(raw))
+	want := []string{"-i", "2", "-r", "-i", "5", "-r"}
+	if strings.Join(got, " ") != strings.Join(want, " ") {
+		t.Fatalf("args=%v want %v", got, want)
+	}
+}
+
 func TestNormalizeNvidiaBenchmarkOptionsPreservesRunNCCLChoice(t *testing.T) {
 	t.Parallel()