Wed, 23 Dec 2009 09:23:54 -0800
6631166: CMS: better heuristics when combatting fragmentation
Summary: Autonomic per-worker free block cache sizing, tunable coalition policies, fixes to per-size block statistics, retuned gain and bandwidth of some feedback loop filters to allow quicker reactivity to abrupt changes in ambient demand, and other heuristics to reduce fragmentation of the CMS old gen. Also tightened some assertions, including those related to locking.
Reviewed-by: jmasa
1 /*
2 * Copyright (c) 2007 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 class ConcurrentMarkSweepPolicy : public TwoGenerationCollectorPolicy {
26 protected:
27 void initialize_generations();
29 public:
30 ConcurrentMarkSweepPolicy();
32 ConcurrentMarkSweepPolicy* as_concurrent_mark_sweep_policy() { return this; }
34 void initialize_gc_policy_counters();
35 #if 1
36 virtual void initialize_size_policy(size_t init_eden_size,
37 size_t init_promo_size,
38 size_t init_survivor_size);
39 #endif
41 // Returns true if the incremental mode is enabled.
42 virtual bool has_soft_ended_eden();
43 };
45 class ASConcurrentMarkSweepPolicy : public ConcurrentMarkSweepPolicy {
46 public:
48 // Initialize the jstat counters. This method requires a
49 // size policy. The size policy is expected to be created
50 // after the generations are fully initialized so the
51 // initialization of the counters need to be done post
52 // the initialization of the generations.
53 void initialize_gc_policy_counters();
55 virtual CollectorPolicy::Name kind() {
56 return CollectorPolicy::ASConcurrentMarkSweepPolicyKind;
57 }
58 };