From c97633b1f58a81296834113299ea93b5e4a0958c Mon Sep 17 00:00:00 2001
From: gmarek <gmarek@google.com>
Date: Mon, 14 Nov 2016 17:38:26 +0100
Subject: [PATCH] Add a flag allowing contention profiling of the API server

---
 hack/verify-flags/known-flags.txt                 |  1 +
 pkg/genericapiserver/config.go                    | 15 +++++++++++----
 .../options/server_run_options.go                 |  4 ++++
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/hack/verify-flags/known-flags.txt b/hack/verify-flags/known-flags.txt
index f15485ab0b1..006d47c98b1 100644
--- a/hack/verify-flags/known-flags.txt
+++ b/hack/verify-flags/known-flags.txt
@@ -106,6 +106,7 @@ container-port
 container-runtime
 container-runtime-endpoint
 contain-pod-resources
+contention-profiling
 controller-start-interval
 cors-allowed-origins
 cpu-cfs-quota
diff --git a/pkg/genericapiserver/config.go b/pkg/genericapiserver/config.go
index ba313d1a037..098a398c6dc 100644
--- a/pkg/genericapiserver/config.go
+++ b/pkg/genericapiserver/config.go
@@ -24,6 +24,7 @@ import (
 	"os"
 	"path"
 	"regexp"
+	goruntime "runtime"
 	"sort"
 	"strconv"
 	"strings"
@@ -78,10 +79,12 @@ type Config struct {
 	// Allows api group versions or specific resources to be conditionally enabled/disabled.
 	APIResourceConfigSource APIResourceConfigSource
 	// allow downstream consumers to disable the index route
-	EnableIndex             bool
-	EnableProfiling         bool
-	EnableMetrics           bool
-	EnableGarbageCollection bool
+	EnableIndex     bool
+	EnableProfiling bool
+	// Requires generic profiling enabled
+	EnableContentionProfiling bool
+	EnableMetrics             bool
+	EnableGarbageCollection   bool
 
 	Version               *version.Info
 	CorsAllowedOriginList []string
@@ -285,6 +288,7 @@ func (c *Config) ApplyOptions(options *options.ServerRunOptions) *Config {
 	c.CorsAllowedOriginList = options.CorsAllowedOriginList
 	c.EnableGarbageCollection = options.EnableGarbageCollection
 	c.EnableProfiling = options.EnableProfiling
+	c.EnableContentionProfiling = options.EnableContentionProfiling
 	c.EnableSwaggerUI = options.EnableSwaggerUI
 	c.ExternalAddress = options.ExternalHost
 	c.MaxRequestsInFlight = options.MaxRequestsInFlight
@@ -462,6 +466,9 @@ func (s *GenericAPIServer) installAPI(c *Config) {
 	}
 	if c.EnableProfiling {
 		routes.Profiling{}.Install(s.HandlerContainer)
+		if c.EnableContentionProfiling {
+			goruntime.SetBlockProfileRate(1)
+		}
 	}
 	if c.EnableMetrics {
 		if c.EnableProfiling {
diff --git a/pkg/genericapiserver/options/server_run_options.go b/pkg/genericapiserver/options/server_run_options.go
index 2047d914208..fd50bbc80ae 100644
--- a/pkg/genericapiserver/options/server_run_options.go
+++ b/pkg/genericapiserver/options/server_run_options.go
@@ -83,6 +83,7 @@ type ServerRunOptions struct {
 	AuditLogMaxSize              int
 	EnableGarbageCollection      bool
 	EnableProfiling              bool
+	EnableContentionProfiling    bool
 	EnableSwaggerUI              bool
 	EnableWatchCache             bool
 	EtcdServersOverrides         []string
@@ -139,6 +140,7 @@ func NewServerRunOptions() *ServerRunOptions {
 		DeleteCollectionWorkers:                  1,
 		EnableGarbageCollection:                  true,
 		EnableProfiling:                          true,
+		EnableContentionProfiling:                false,
 		EnableWatchCache:                         true,
 		InsecureBindAddress:                      net.ParseIP("127.0.0.1"),
 		InsecurePort:                             8080,
@@ -347,6 +349,8 @@ func (s *ServerRunOptions) AddUniversalFlags(fs *pflag.FlagSet) {
 
 	fs.BoolVar(&s.EnableProfiling, "profiling", s.EnableProfiling,
 		"Enable profiling via web interface host:port/debug/pprof/")
+	fs.BoolVar(&s.EnableContentionProfiling, "contention-profiling", s.EnableContentionProfiling,
+		"Enable contention profiling. Requires --profiling to be set to work.")
 
 	fs.BoolVar(&s.EnableSwaggerUI, "enable-swagger-ui", s.EnableSwaggerUI,
 		"Enables swagger ui on the apiserver at /swagger-ui")