net/http/pprof: note calling runtime.SetBlockProfileRate is required for block profile

Fixes #15076

Change-Id: I5ce8f6253245d8cc1f862a1bf618775f557f955d
Reviewed-on: https://go-review.googlesource.com/21610
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/net/http/pprof/pprof.go b/src/net/http/pprof/pprof.go
index 2357d8ed1ede411aff0980e215cff34cf3e0caf2..44afa2d8d89ad2cb1b8391796b80794831220a6e 100644 (file)
--- a/src/net/http/pprof/pprof.go
+++ b/src/net/http/pprof/pprof.go
@@ -30,7 +30,8 @@
 //
 //     go tool pprof http://localhost:6060/debug/pprof/profile
 //
-// Or to look at the goroutine blocking profile:
+// Or to look at the goroutine blocking profile, after calling
+// runtime.SetBlockProfileRate in your program:
 //
 //     go tool pprof http://localhost:6060/debug/pprof/block
 //