From 5e41fe0e45c66bf7359988551a321137e2ddfe89 Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Mon, 5 Mar 2012 22:47:23 -0500
Subject: [PATCH] build: use run.go for running tests

Also, tweak run.go to use no more than 2x the
number of CPUs, and only one on ARM.

53.85u 13.33s 53.69r 	 ./run
50.68u 12.13s 18.85r 	 go run run.go

Fixes #2833.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5754047
---
 src/run.bash | 2 +-
 src/run.bat  | 9 ++++++++-
 test/run.go  | 7 +++++--
 3 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/run.bash b/src/run.bash
index fdbf47663bb..7b1854865ef 100755
--- a/src/run.bash
+++ b/src/run.bash
@@ -105,7 +105,7 @@ $BROKEN ||
 ) || exit $?
 
 (xcd ../test
-./run
+time go run run.go
 ) || exit $?
 
 echo
diff --git a/src/run.bat b/src/run.bat
index 9f2af3978b5..f1eebe374a3 100644
--- a/src/run.bat
+++ b/src/run.bat
@@ -36,7 +36,14 @@ go test sync -short -timeout=120s -cpu=10
 if errorlevel 1 goto fail
 echo.
 
-:: TODO: The other tests in run.bash, especially $GOROOT/test/run.
+:: TODO: The other tests in run.bash.
+
+echo # test
+cd test
+go run run.go
+cd ..
+if errorlevel 1 goto fail
+echo.
 
 echo ALL TESTS PASSED
 goto end
diff --git a/test/run.go b/test/run.go
index 050cfadb2c6..f0b2555db07 100644
--- a/test/run.go
+++ b/test/run.go
@@ -30,7 +30,7 @@ import (
 
 var (
 	verbose     = flag.Bool("v", false, "verbose. if set, parallelism is set to 1.")
-	numParallel = flag.Int("n", 8, "number of parallel tests to run")
+	numParallel = flag.Int("n", 2*runtime.NumCPU(), "number of parallel tests to run")
 	summary     = flag.Bool("summary", false, "show summary of results")
 	showSkips   = flag.Bool("show_skips", false, "show skipped tests")
 )
@@ -60,7 +60,10 @@ const maxTests = 5000
 
 func main() {
 	flag.Parse()
-	if *verbose {
+	
+	// Disable parallelism if printing, or if running on
+	// (presumably underpowered) arm systems.
+	if *verbose || runtime.GOARCH == "arm" {
 		*numParallel = 1
 	}