8309403: Serial: Remove the useless adaptive size policy in GenCollectedHeap

Reviewed-by: ayang, tschatzl

src/hotspot/share/gc/serial/defNewGeneration.cpp

@@ -830,10 +830,6 @@ void DefNewGeneration::collect(bool   full,
 
     adjust_desired_tenuring_threshold();
 
-    // A successful scavenge should restart the GC time limit count which is
-    // for full GC's.
-    AdaptiveSizePolicy* size_policy = heap->size_policy();
-    size_policy->reset_gc_overhead_limit_count();
     assert(!heap->incremental_collection_failed(), "Should be clear");
   } else {
     assert(_promo_failure_scan_stack.is_empty(), "post condition");

src/hotspot/share/gc/shared/genCollectedHeap.cpp

@@ -95,8 +95,7 @@ GenCollectedHeap::GenCollectedHeap(Generation::Name young,
                                    MaxOldSize,
                                    GenAlignment)),
   _rem_set(nullptr),
-  _soft_ref_gen_policy(),
-  _size_policy(nullptr),
+  _soft_ref_policy(),
   _gc_policy_counters(new GCPolicyCounters(policy_counters_name, 2, 2)),
   _incremental_collection_failed(false),
   _full_collections_completed(0),
@@ -139,17 +138,6 @@ CardTableRS* GenCollectedHeap::create_rem_set(const MemRegion& reserved_region)
   return new CardTableRS(reserved_region);
 }
 
-void GenCollectedHeap::initialize_size_policy(size_t init_eden_size,
-                                              size_t init_promo_size,
-                                              size_t init_survivor_size) {
-  const double max_gc_pause_sec = ((double) MaxGCPauseMillis) / 1000.0;
-  _size_policy = new AdaptiveSizePolicy(init_eden_size,
-                                        init_promo_size,
-                                        init_survivor_size,
-                                        max_gc_pause_sec,
-                                        GCTimeRatio);
-}
-
 ReservedHeapSpace GenCollectedHeap::allocate(size_t alignment) {
   // Now figure out the total size.
   const size_t pageSize = UseLargePages ? os::large_page_size() : os::vm_page_size();
@@ -194,10 +182,6 @@ void GenCollectedHeap::post_initialize() {
 
   def_new_gen->ref_processor_init();
 
-  initialize_size_policy(def_new_gen->eden()->capacity(),
-                         _old_gen->capacity(),
-                         def_new_gen->from()->capacity());
-
   MarkSweep::initialize();
 
   ScavengableNMethods::initialize(&_is_scavengable);

src/hotspot/share/gc/shared/genCollectedHeap.hpp

@@ -29,7 +29,7 @@
 #include "gc/shared/generation.hpp"
 #include "gc/shared/oopStorageParState.hpp"
 #include "gc/shared/preGCValues.hpp"
-#include "gc/shared/softRefGenPolicy.hpp"
+#include "gc/shared/softRefPolicy.hpp"
 
 class AdaptiveSizePolicy;
 class CardTableRS;
@@ -72,10 +72,7 @@ private:
   // The singleton CardTable Remembered Set.
   CardTableRS* _rem_set;
 
-  SoftRefGenPolicy _soft_ref_gen_policy;
-
-  // The sizing of the heap is controlled by a sizing policy.
-  AdaptiveSizePolicy* _size_policy;
+  SoftRefPolicy _soft_ref_policy;
 
   GCPolicyCounters* _gc_policy_counters;
 
@@ -139,10 +136,6 @@ public:
   jint initialize() override;
   virtual CardTableRS* create_rem_set(const MemRegion& reserved_region);
 
-  void initialize_size_policy(size_t init_eden_size,
-                              size_t init_promo_size,
-                              size_t init_survivor_size);
-
   // Does operations required after initialization has been done.
   void post_initialize() override;
 
@@ -158,12 +151,7 @@ public:
   GenerationSpec* young_gen_spec() const;
   GenerationSpec* old_gen_spec() const;
 
-  SoftRefPolicy* soft_ref_policy() override { return &_soft_ref_gen_policy; }
-
-  // Adaptive size policy
-  virtual AdaptiveSizePolicy* size_policy() {
-    return _size_policy;
-  }
+  SoftRefPolicy* soft_ref_policy() override { return &_soft_ref_policy; }
 
   // Performance Counter support
   GCPolicyCounters* counters()     { return _gc_policy_counters; }

src/hotspot/share/gc/shared/softRefGenPolicy.cpp

@@ -1,40 +0,0 @@
-/*
- * Copyright (c) 2001, 2023, 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
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-#include "precompiled.hpp"
-#include "gc/shared/adaptiveSizePolicy.hpp"
-#include "gc/shared/genCollectedHeap.hpp"
-#include "gc/shared/softRefGenPolicy.hpp"
-
-void SoftRefGenPolicy::cleared_all_soft_refs() {
-  // If near gc overhear limit, continue to clear SoftRefs.  SoftRefs may
-  // have been cleared in the last collection but if the gc overhear
-  // limit continues to be near, SoftRefs should still be cleared.
-  AdaptiveSizePolicy* size_policy = GenCollectedHeap::heap()->size_policy();
-  if (size_policy != nullptr) {
-    set_should_clear_all_soft_refs(size_policy->gc_overhead_limit_near());
-  }
-
-  SoftRefPolicy::cleared_all_soft_refs();
-}

src/hotspot/share/gc/shared/softRefGenPolicy.hpp

@@ -1,38 +0,0 @@
-/*
- * Copyright (c) 2001, 2019, 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
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-#ifndef SHARE_GC_SHARED_SOFTREFGENPOLICY_HPP
-#define SHARE_GC_SHARED_SOFTREFGENPOLICY_HPP
-
-#include "gc/shared/softRefPolicy.hpp"
-#include "utilities/globalDefinitions.hpp"
-
-class AdaptiveSizePolicy;
-
-class SoftRefGenPolicy : public SoftRefPolicy {
-public:
-  virtual void cleared_all_soft_refs();
-};
-
-#endif // SHARE_GC_SHARED_SOFTREFGENPOLICY_HPP

src/hotspot/share/prims/whitebox.cpp

@@ -1445,12 +1445,12 @@ WB_END
 WB_ENTRY(void, WB_FullGC(JNIEnv* env, jobject o))
   Universe::heap()->soft_ref_policy()->set_should_clear_all_soft_refs(true);
   Universe::heap()->collect(GCCause::_wb_full_gc);
-#if INCLUDE_G1GC
-  if (UseG1GC) {
-    // Needs to be cleared explicitly for G1
+#if INCLUDE_G1GC || INCLUDE_SERIALGC
+  if (UseG1GC || UseSerialGC) {
+    // Needs to be cleared explicitly for G1 and Serial GC.
     Universe::heap()->soft_ref_policy()->set_should_clear_all_soft_refs(false);
   }
-#endif // INCLUDE_G1GC
+#endif // INCLUDE_G1GC || INCLUDE_SERIALGC
 WB_END
 
 WB_ENTRY(void, WB_YoungGC(JNIEnv* env, jobject o))