From b2f33e8a70d5224a1a1b0c686fd2d974503f1e53 Mon Sep 17 00:00:00 2001
From: tschatzl <unknown>
Date: Thu, 15 Dec 2016 20:00:01 -0500
Subject: [PATCH] 8161993: G1 crashes if active_processor_count changes during
 startup Summary: Use the initial active processor count for memory
 initialization instead of the current active one. Reviewed-by: dholmes,
 mgerdin

---
 src/share/vm/gc_implementation/g1/concurrentMark.cpp | 7 +++----
 src/share/vm/gc_implementation/g1/dirtyCardQueue.cpp | 4 ++--
 src/share/vm/runtime/vm_version.cpp                  | 4 ++--
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/share/vm/gc_implementation/g1/concurrentMark.cpp b/src/share/vm/gc_implementation/g1/concurrentMark.cpp
index 92261912a..a5c426142 100644
--- a/src/share/vm/gc_implementation/g1/concurrentMark.cpp
+++ b/src/share/vm/gc_implementation/g1/concurrentMark.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -631,11 +631,10 @@ ConcurrentMark::ConcurrentMark(G1CollectedHeap* g1h, G1RegionToSpaceMapper* prev
       double overall_cm_overhead =
         (double) MaxGCPauseMillis * marking_overhead /
         (double) GCPauseIntervalMillis;
-      double cpu_ratio = 1.0 / (double) os::processor_count();
+      double cpu_ratio = 1.0 / os::initial_active_processor_count();
       double marking_thread_num = ceil(overall_cm_overhead / cpu_ratio);
       double marking_task_overhead =
-        overall_cm_overhead / marking_thread_num *
-                                                (double) os::processor_count();
+        overall_cm_overhead / marking_thread_num * os::initial_active_processor_count();
       double sleep_factor =
                          (1.0 - marking_task_overhead) / marking_task_overhead;
 
diff --git a/src/share/vm/gc_implementation/g1/dirtyCardQueue.cpp b/src/share/vm/gc_implementation/g1/dirtyCardQueue.cpp
index 6e84e514a..62555c974 100644
--- a/src/share/vm/gc_implementation/g1/dirtyCardQueue.cpp
+++ b/src/share/vm/gc_implementation/g1/dirtyCardQueue.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -80,7 +80,7 @@ DirtyCardQueueSet::DirtyCardQueueSet(bool notify_when_complete) :
 
 // Determines how many mutator threads can process the buffers in parallel.
 uint DirtyCardQueueSet::num_par_ids() {
-  return (uint)os::processor_count();
+  return (uint)os::initial_active_processor_count();
 }
 
 void DirtyCardQueueSet::initialize(CardTableEntryClosure* cl, Monitor* cbl_mon, Mutex* fl_lock,
diff --git a/src/share/vm/runtime/vm_version.cpp b/src/share/vm/runtime/vm_version.cpp
index a046d8142..d95e3a966 100644
--- a/src/share/vm/runtime/vm_version.cpp
+++ b/src/share/vm/runtime/vm_version.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -296,7 +296,7 @@ unsigned int Abstract_VM_Version::nof_parallel_worker_threads(
     // processor after the first 8.  For example, on a 72 cpu machine
     // and a chosen fraction of 5/8
     // use 8 + (72 - 8) * (5/8) == 48 worker threads.
-    unsigned int ncpus = (unsigned int) os::active_processor_count();
+    unsigned int ncpus = (unsigned int) os::initial_active_processor_count();
     return (ncpus <= switch_pt) ?
            ncpus :
           (switch_pt + ((ncpus - switch_pt) * num) / den);
-- 
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