From: Felix Geisendörfer <felix.geisendoerfer@datadoghq.com>
Date: Wed, 2 Nov 2022 08:28:54 +0000 (+0100)
Subject: testing: Document RunParallel ns/op behavior
X-Git-Tag: go1.20rc1~405
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=8ec1c9e2850c642e3ebd0ea3a9749dd13cd4545a;p=gostls13.git

testing: Document RunParallel ns/op behavior

Updates #31884

Change-Id: Ibad3d31038a8426c0bce61c1726392880f934865
Reviewed-on: https://go-review.googlesource.com/c/go/+/447136
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>
Auto-Submit: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
---

diff --git a/src/testing/benchmark.go b/src/testing/benchmark.go
index 31fc7d7156..be9b87f80b 100644
--- a/src/testing/benchmark.go
+++ b/src/testing/benchmark.go
@@ -777,6 +777,9 @@ func (pb *PB) Next() bool {
 // goroutine-local state and then iterate until pb.Next returns false.
 // It should not use the StartTimer, StopTimer, or ResetTimer functions,
 // because they have global effect. It should also not call Run.
+//
+// RunParallel reports ns/op values as wall time for the benchmark as a whole,
+// not the sum of wall time or CPU time over each parallel goroutine.
 func (b *B) RunParallel(body func(*PB)) {
 	if b.N == 0 {
 		return // Nothing to do when probing.