unshare mounts to avoid systemd bottlenecking on mount discovery

Author: tylerharter

scripts/bin_test.py

@@ -86,8 +86,6 @@ def _main():
 
         registry = os.path.abspath(args.registry)
         with TestConfContext(registry=registry):
-            print(f"Using registry: {registry}")
-            print(f"Contents: {os.listdir(registry)}")
             run_tests()
 
     check_test_results()

src/bench/bench.go

@@ -95,7 +95,7 @@ func run_benchmark(ctx *cli.Context, name string, seconds float64, tasks int, fu
                 case err := <- errQ:
 			if err != nil {
 				errors += 1
-				fmt.Printf(err.Error())
+				fmt.Printf("%s\n", err.Error())
 			} else {
 				successes += 1
 			}
@@ -180,7 +180,7 @@ func BenchCommands() []cli.Command {
 				parseq = "par"
 			}
 			amt := fmt.Sprintf("%d", functions)
-			if functions > 1024 {
+			if functions >= 1024 {
 				amt = fmt.Sprintf("%dk", functions / 1024)
 			}
 			name := fmt.Sprintf("py%s-%s", amt, parseq)

src/main.go

@@ -158,9 +158,16 @@ func worker(ctx *cli.Context) error {
 		if err != nil {
 			return err
 		}
-		// holds attributes that will be used when os.StartProcess
+		// holds attributes that will be used when os.StartProcess.
+		// we use CLONE_NEWNS because ol creates many mount points.
+		// we don't want them to show up in /proc/self/mountinfo
+		// for systemd because systemd creates a service for each
+		// mount point, which is a major overhead.
 		attr := os.ProcAttr{
 			Files: []*os.File{nil, f, f},
+			Sys: &syscall.SysProcAttr{
+				Unshareflags: syscall.CLONE_NEWNS,
+			},
 		}
 		cmd := []string{}
 		for _, arg := range os.Args {