From 4956880699c1947cab78e7b3db1f705e731815d3 Mon Sep 17 00:00:00 2001
From: Stefan Johansson <sjohanss@openjdk.org>
Date: Fri, 29 Apr 2016 08:39:22 +0200
Subject: [PATCH] 8155245: Add logging when MMU target is violated

Reviewed-by: ehelin, mgerdin
---
 hotspot/src/share/vm/gc/g1/g1MMUTracker.cpp | 5 +++++
 hotspot/src/share/vm/logging/logPrefix.hpp  | 1 +
 hotspot/src/share/vm/logging/logTag.hpp     | 1 +
 3 files changed, 7 insertions(+)

diff --git a/hotspot/src/share/vm/gc/g1/g1MMUTracker.cpp b/hotspot/src/share/vm/gc/g1/g1MMUTracker.cpp
index e8c7a4e9f9b..fdb99afe7b7 100644
--- a/hotspot/src/share/vm/gc/g1/g1MMUTracker.cpp
+++ b/hotspot/src/share/vm/gc/g1/g1MMUTracker.cpp
@@ -25,6 +25,7 @@
 #include "precompiled.hpp"
 #include "gc/g1/g1MMUTracker.hpp"
 #include "gc/shared/gcTrace.hpp"
+#include "logging/log.hpp"
 #include "runtime/mutexLocker.hpp"
 #include "utilities/ostream.hpp"
 
@@ -107,6 +108,10 @@ void G1MMUTrackerQueue::add_pause(double start, double end) {
   // Current entry needs to be added before calculating the value
   double slice_time = calculate_gc_time(end);
   G1MMUTracer::report_mmu(_time_slice, slice_time, _max_gc_time);
+
+  if (slice_time >= _max_gc_time) {
+    log_info(gc, mmu)("MMU target violated: %.1lfms (%.1lfms/%.1lfms)", slice_time * 1000.0, _max_gc_time * 1000.0, _time_slice * 1000);
+  }
 }
 
 // basically the _internal call does not remove expired entries
diff --git a/hotspot/src/share/vm/logging/logPrefix.hpp b/hotspot/src/share/vm/logging/logPrefix.hpp
index 8d2ae12adf3..7e4da0f058e 100644
--- a/hotspot/src/share/vm/logging/logPrefix.hpp
+++ b/hotspot/src/share/vm/logging/logPrefix.hpp
@@ -64,6 +64,7 @@ DEBUG_ONLY(size_t Test_log_prefix_prefixer(char* buf, size_t len);)
   LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, liveness)) \
   LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, marking)) \
   LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, metaspace)) \
+  LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, mmu)) \
   LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, phases)) \
   LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, phases, start)) \
   LOG_PREFIX(GCId::print_prefix, LOG_TAGS(gc, phases, task)) \
diff --git a/hotspot/src/share/vm/logging/logTag.hpp b/hotspot/src/share/vm/logging/logTag.hpp
index d9759dca859..1f0a1c31e2c 100644
--- a/hotspot/src/share/vm/logging/logTag.hpp
+++ b/hotspot/src/share/vm/logging/logTag.hpp
@@ -67,6 +67,7 @@
   LOG_TAG(logging) \
   LOG_TAG(marking) \
   LOG_TAG(metaspace) \
+  LOG_TAG(mmu) \
   LOG_TAG(modules) \
   LOG_TAG(monitorinflation) \
   LOG_TAG(monitormismatch) \