code review 5754047: build: use run.go for running tests

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 issue 2833.

[rsc, 2012-03-06 03:26:02]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://code.google.com/p/go/

[bradfitz, 2012-03-06 03:38:50]

LGTM

"Fixes issue 2833"


On Mon, Mar 5, 2012 at 7:26 PM, <rsc@golang.org> wrote:

> Reviewers: golang-dev_googlegroups.com,
>
> Message:
> Hello golang-dev@googlegroups.com,
>
> I'd like you to review this change to
> https://code.google.com/p/go/
>
>
> Description:
> 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
>
> Please review this at
http://codereview.appspot.com/**5754047/<http://codereview.appspot.com/5754047/>
>
> Affected files:
>  M src/run.bash
>  M src/run.bat
>  M test/run.go
>
>
> Index: src/run.bash
> ==============================**==============================**=======
> --- a/src/run.bash
> +++ b/src/run.bash
> @@ -105,7 +105,7 @@
>  ) || exit $?
>
>  (xcd ../test
> -./run
> +time go run run.go
>  ) || exit $?
>
>  echo
> Index: src/run.bat
> ==============================**==============================**=======
> --- a/src/run.bat
> +++ b/src/run.bat
> @@ -36,7 +36,14 @@
>  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
> Index: test/run.go
> ==============================**==============================**=======
> --- a/test/run.go
> +++ b/test/run.go
> @@ -30,7 +30,7 @@
>
>  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 @@
>
>  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
>        }
>
>
>
>

[rsc, 2012-03-06 03:47:26]

*** Submitted as 603ac92ed3a7 ***

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 issue 2833.

R=golang-dev, bradfitz
CC=golang-dev
http://codereview.appspot.com/5754047

[minux1, 2012-03-06 14:22:05]

On Tue, Mar 6, 2012 at 11:47 AM, <rsc@golang.org> wrote:
>
>  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.
>
The Linux/ARM builder has two CPU cores, and currently this part of test
takes most of the
time. I believe it will receive some speedup if we set it to runtime.NumCPU()
instead of 1
(it certainly won't hurt ARM machines with only 1 core, but it will speed
up the multicore
machines.)

Some statistics on idle builder with tmpfs holding ~/work2:
minux@omap4460:~/work2/go/test$ /usr/bin/time go run run.go -n=4
290.89user 37.23system 2:53.16elapsed 189%CPU (0avgtext+0avgdata
304368maxresident)k
0inputs+0outputs (0major+3202559minor)pagefaults 0swaps

minux@omap4460:~/work2/go/test$ /usr/bin/time go run run.go -n=3
289.71user 36.03system 2:51.91elapsed 189%CPU (0avgtext+0avgdata
304448maxresident)k
0inputs+0outputs (0major+3195588minor)pagefaults 0swaps

minux@omap4460:~/work2/go/test$ /usr/bin/time go run run.go -n=2
288.66user 35.11system 2:52.45elapsed 187%CPU (0avgtext+0avgdata
304368maxresident)k
0inputs+0outputs (0major+3192096minor)pagefaults 0swaps

minux@omap4460:~/work2/go/test$ /usr/bin/time go run run.go -n=1
290.06user 35.67system 5:31.61elapsed 98%CPU (0avgtext+0avgdata
304368maxresident)k
0inputs+0outputs (0major+3179289minor)pagefaults 0swaps

minux@omap4460:~/work2/go/test$ /usr/bin/time ./run &>/dev/null
263.31user 36.98system 5:28.20elapsed 91%CPU (0avgtext+0avgdata
1165424maxresident)k
0inputs+0outputs (0major+3948024minor)pagefaults 0swaps

I've made a CL for this: http://codereview.appspot.com/5753054.