code review 166060: testing: compute MB/s in benchmarks

testing: compute MB/s in benchmarks

[rsc, 2009-12-04 17:34:09]

Hello r,

I'd like you to review the following change.

[r2, 2009-12-04 17:44:24]

LGTM

On Dec 4, 2009, at 9:34 AM, rsc@golang.org wrote:

> Reviewers: r,
> 
> Message:
> Hello r,
> 
> I'd like you to review the following change.
> 
> 
> Description:
> testing: compute MB/s in benchmarks
> 
> Please review this at http://codereview.appspot.com/166060
> 
> Affected files:
>  M src/pkg/testing/benchmark.go
> 
> 
> Index: src/pkg/testing/benchmark.go
> ===================================================================
> --- a/src/pkg/testing/benchmark.go
> +++ b/src/pkg/testing/benchmark.go
> @@ -26,6 +26,7 @@
> 	N		int;
> 	benchmark	Benchmark;
> 	ns		int64;
> +	bytes		int64;
> 	start		int64;
> }
> 
> @@ -50,6 +51,10 @@
> 	b.ns = 0;
> }
> 
> +// SetBytes records the number of bytes processed in a single operation.
> +// If this is called, the benchmark will report ns/op and MB/s.
> +func (b *B) SetBytes(n int64)	{ b.bytes = n }
> +
> func (b *B) nsPerOp() int64 {
> 	if b.N <= 0 {
> 		return 0
> @@ -125,7 +130,12 @@
> 		n = roundUp(n);
> 		b.runN(n);
> 	}
> -	fmt.Printf("%s\t%d\t%10d ns/op\n", b.benchmark.Name, b.N, b.nsPerOp());
> +	ns := b.nsPerOp();
> +	mb := "";
> +	if ns > 0 && b.bytes > 0 {
> +		mb = fmt.Sprintf("\t%7.2f MB/s", (float64(b.bytes)/1e6)/(float64(ns)/1e9))
> +	}
> +	fmt.Printf("%s\t%8d\t%10d ns/op%s\n", b.benchmark.Name, b.N, b.nsPerOp(),
mb);
> }
> 
> // An internal function but exported because it is cross-package; part of the
implementation
> 
> 

[rsc, 2009-12-04 17:56:34]

*** Submitted as http://code.google.com/p/go/source/detail?r=8db2fdef9145 ***

testing: compute MB/s in benchmarks

R=r
http://codereview.appspot.com/166060