1 files changed, 19 insertions, 7 deletions
diff --git a/src/pkg/testing/benchmark.go b/src/pkg/testing/benchmark.go
index cf73e2b48..f8b53e63a 100644
--- a/src/pkg/testing/benchmark.go
+++ b/src/pkg/testing/benchmark.go
@@ -143,14 +143,13 @@ func (b *B) run() BenchmarkResult {
 		b.runN(n)
 	}
 	return BenchmarkResult{b.N, b.ns, b.bytes}
-
 }
 
 // The results of a benchmark run.
 type BenchmarkResult struct {
 	N     int   // The number of iterations.
 	Ns    int64 // The total time taken.
-	Bytes int64 // The total number of bytes processed.
+	Bytes int64 // Bytes processed in one iteration.
 }
 
 func (r BenchmarkResult) NsPerOp() int64 {
@@ -160,13 +159,20 @@ func (r BenchmarkResult) NsPerOp() int64 {
 	return r.Ns / int64(r.N)
 }
 
+func (r BenchmarkResult) mbPerSec() float64 {
+	if r.Bytes <= 0 || r.Ns <= 0 || r.N <= 0 {
+		return 0
+	}
+	return float64(r.Bytes) * float64(r.N) / float64(r.Ns) * 1e3
+}
+
 func (r BenchmarkResult) String() string {
-	ns := r.NsPerOp()
+	mbs := r.mbPerSec()
 	mb := ""
-	if ns > 0 && r.Bytes > 0 {
-		mb = fmt.Sprintf("\t%7.2f MB/s", (float64(r.Bytes)/1e6)/(float64(ns)/1e9))
+	if mbs != 0 {
+		mb = fmt.Sprintf("\t%7.2f MB/s", mbs)
 	}
-	return fmt.Sprintf("%8d\t%10d ns/op%s", r.N, ns, mb)
+	return fmt.Sprintf("%8d\t%10d ns/op%s", r.N, r.NsPerOp(), mb)
 }
 
 // An internal function but exported because it is cross-package; part of the implementation
@@ -176,6 +182,7 @@ func RunBenchmarks(matchString func(pat, str string) (bool, os.Error), benchmark
 	if len(*matchBenchmarks) == 0 {
 		return
 	}
+	procs := runtime.GOMAXPROCS(-1)
 	for _, Benchmark := range benchmarks {
 		matched, err := matchString(*matchBenchmarks, Benchmark.Name)
 		if err != nil {
@@ -187,7 +194,12 @@ func RunBenchmarks(matchString func(pat, str string) (bool, os.Error), benchmark
 		}
 		b := &B{benchmark: Benchmark}
 		r := b.run()
-		fmt.Printf("%s\t%v\n", Benchmark.Name, r)
+		print(fmt.Sprintf("%s\t%v\n", Benchmark.Name, r))
+		if p := runtime.GOMAXPROCS(-1); p != procs {
+			print(fmt.Sprintf("%s left GOMAXPROCS set to %d\n", Benchmark.Name, p))
+			procs = p
+		}
+
 	}
 }