code review 4657053: testing: scale benchmark precision to 0.01ns if needed

testing: scale benchmark precision to 0.01ns if needed

[rsc, 2011-06-27 19:03:54]

Hello dvyukov@google.com (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://go.googlecode.com/hg

[dvyukov, 2011-06-27 19:43:09]

Other than that, LGTM.

http://codereview.appspot.com/4657053/diff/1/src/pkg/testing/benchmark.go
File src/pkg/testing/benchmark.go (right):

http://codereview.appspot.com/4657053/diff/1/src/pkg/testing/benchmark.go#new...
src/pkg/testing/benchmark.go:183: ns = fmt.Sprintf("%12.1f ns/op", float64(r.Ns)
/ float64(r.N))
Currently it looks like:
sync_test.BenchmarkOnce-2	 5000000	       113 ns/op
sync_test.BenchmarkOnce-4	10000000	        63.6 ns/op
sync_test.BenchmarkOnce-8	50000000	        11.4 ns/op
sync_test.BenchmarkOnce-16	100000000	         6.75 ns/op

I would suggest "%10.2f" and "%10.1f" (width includes precision), then it looks
like:
sync_test.BenchmarkOnce-2	 5000000	       114 ns/op
sync_test.BenchmarkOnce-4	10000000	      61.6 ns/op
sync_test.BenchmarkOnce-8	50000000	      11.3 ns/op
sync_test.BenchmarkOnce-16	100000000	      6.65 ns/op

[rsc, 2011-06-27 19:44:56]

> Currently it looks like:
> sync_test.BenchmarkOnce-2        5000000               113 ns/op
> sync_test.BenchmarkOnce-4       10000000                63.6 ns/op
> sync_test.BenchmarkOnce-8       50000000                11.4 ns/op
> sync_test.BenchmarkOnce-16      100000000                6.75 ns/op

I did this on purpose, so that the ones digits all line up.

[r2, 2011-06-27 21:33:08]

LGTM

[rsc, 2011-06-27 22:50:34]

*** Submitted as http://code.google.com/p/go/source/detail?r=1d3fd52f578f ***

testing: scale benchmark precision to 0.01ns if needed

R=dvyukov, r
CC=golang-dev
http://codereview.appspot.com/4657053