From: Josh Bleecher Snyder <josharian@gmail.com>
Date: Thu, 14 May 2015 02:27:59 +0000 (-0700)
Subject: encoding/json: make BenchmarkSkipValue more stable
X-Git-Tag: go1.5beta1~602
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=dbf533a5460d7fcc7d7be77014fd74a8aff8c412;p=gostls13.git

encoding/json: make BenchmarkSkipValue more stable

BenchmarkSkipValue was sensitive to the value of
b.N due to its significant startup cost.

Two adjacent runs before this CL:

BenchmarkSkipValue	      50	  21047499 ns/op	  93.37 MB/s
BenchmarkSkipValue	     100	  17260554 ns/op	 118.05 MB/s

After this CL, using benchtime to recreate the
difference in b.N:

BenchmarkSkipValue	      50	  15204797 ns/op	 131.67 MB/s
BenchmarkSkipValue	     100	  15332319 ns/op	 130.58 MB/s

Change-Id: Iac86f86dd774d535302fa5e4c08f89f8da00be9e
Reviewed-on: https://go-review.googlesource.com/10053
Reviewed-by: Andrew Gerrand <adg@golang.org>
---

diff --git a/src/encoding/json/scanner_test.go b/src/encoding/json/scanner_test.go
index 7880342902..66383ef0ef 100644
--- a/src/encoding/json/scanner_test.go
+++ b/src/encoding/json/scanner_test.go
@@ -209,6 +209,7 @@ var benchScan scanner
 
 func BenchmarkSkipValue(b *testing.B) {
 	initBig()
+	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		nextValue(jsonBig, &benchScan)
 	}