Mon, 28 Jul 2008 15:30:23 -0700
Merge
1 /*
2 * Copyright 2006-2008 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 /*
26 * The NUMA-aware allocator (MutableNUMASpace) is basically a modification
27 * of MutableSpace which preserves interfaces but implements different
28 * functionality. The space is split into chunks for each locality group
29 * (resizing for adaptive size policy is also supported). For each thread
30 * allocations are performed in the chunk corresponding to the home locality
31 * group of the thread. Whenever any chunk fills-in the young generation
32 * collection occurs.
33 * The chunks can be also be adaptively resized. The idea behind the adaptive
34 * sizing is to reduce the loss of the space in the eden due to fragmentation.
35 * The main cause of fragmentation is uneven allocation rates of threads.
36 * The allocation rate difference between locality groups may be caused either by
37 * application specifics or by uneven LWP distribution by the OS. Besides,
38 * application can have less threads then the number of locality groups.
39 * In order to resize the chunk we measure the allocation rate of the
40 * application between collections. After that we reshape the chunks to reflect
41 * the allocation rate pattern. The AdaptiveWeightedAverage exponentially
42 * decaying average is used to smooth the measurements. The NUMASpaceResizeRate
43 * parameter is used to control the adaptation speed by restricting the number of
44 * bytes that can be moved during the adaptation phase.
45 * Chunks may contain pages from a wrong locality group. The page-scanner has
46 * been introduced to address the problem. Remote pages typically appear due to
47 * the memory shortage in the target locality group. Besides Solaris would
48 * allocate a large page from the remote locality group even if there are small
49 * local pages available. The page-scanner scans the pages right after the
50 * collection and frees remote pages in hope that subsequent reallocation would
51 * be more successful. This approach proved to be useful on systems with high
52 * load where multiple processes are competing for the memory.
53 */
55 class MutableNUMASpace : public MutableSpace {
56 friend class VMStructs;
58 class LGRPSpace : public CHeapObj {
59 int _lgrp_id;
60 MutableSpace* _space;
61 MemRegion _invalid_region;
62 AdaptiveWeightedAverage *_alloc_rate;
64 struct SpaceStats {
65 size_t _local_space, _remote_space, _unbiased_space, _uncommited_space;
66 size_t _large_pages, _small_pages;
68 SpaceStats() {
69 _local_space = 0;
70 _remote_space = 0;
71 _unbiased_space = 0;
72 _uncommited_space = 0;
73 _large_pages = 0;
74 _small_pages = 0;
75 }
76 };
78 SpaceStats _space_stats;
80 char* _last_page_scanned;
81 char* last_page_scanned() { return _last_page_scanned; }
82 void set_last_page_scanned(char* p) { _last_page_scanned = p; }
83 public:
84 LGRPSpace(int l) : _lgrp_id(l), _last_page_scanned(NULL) {
85 _space = new MutableSpace();
86 _alloc_rate = new AdaptiveWeightedAverage(NUMAChunkResizeWeight);
87 }
88 ~LGRPSpace() {
89 delete _space;
90 delete _alloc_rate;
91 }
93 void add_invalid_region(MemRegion r) {
94 if (!_invalid_region.is_empty()) {
95 _invalid_region.set_start(MIN2(_invalid_region.start(), r.start()));
96 _invalid_region.set_end(MAX2(_invalid_region.end(), r.end()));
97 } else {
98 _invalid_region = r;
99 }
100 }
102 static bool equals(void* lgrp_id_value, LGRPSpace* p) {
103 return *(int*)lgrp_id_value == p->lgrp_id();
104 }
106 void sample() {
107 alloc_rate()->sample(space()->used_in_bytes());
108 }
110 MemRegion invalid_region() const { return _invalid_region; }
111 void set_invalid_region(MemRegion r) { _invalid_region = r; }
112 int lgrp_id() const { return _lgrp_id; }
113 MutableSpace* space() const { return _space; }
114 AdaptiveWeightedAverage* alloc_rate() const { return _alloc_rate; }
115 void clear_alloc_rate() { _alloc_rate->clear(); }
116 SpaceStats* space_stats() { return &_space_stats; }
117 void clear_space_stats() { _space_stats = SpaceStats(); }
119 void accumulate_statistics(size_t page_size);
120 void scan_pages(size_t page_size, size_t page_count);
121 };
123 GrowableArray<LGRPSpace*>* _lgrp_spaces;
124 size_t _page_size;
125 unsigned _adaptation_cycles, _samples_count;
127 void set_page_size(size_t psz) { _page_size = psz; }
128 size_t page_size() const { return _page_size; }
130 unsigned adaptation_cycles() { return _adaptation_cycles; }
131 void set_adaptation_cycles(int v) { _adaptation_cycles = v; }
133 unsigned samples_count() { return _samples_count; }
134 void increment_samples_count() { ++_samples_count; }
136 size_t _base_space_size;
137 void set_base_space_size(size_t v) { _base_space_size = v; }
138 size_t base_space_size() const { return _base_space_size; }
140 // Check if the NUMA topology has changed. Add and remove spaces if needed.
141 // The update can be forced by setting the force parameter equal to true.
142 bool update_layout(bool force);
143 // Bias region towards the lgrp.
144 void bias_region(MemRegion mr, int lgrp_id);
145 // Free pages in a given region.
146 void free_region(MemRegion mr);
147 // Get current chunk size.
148 size_t current_chunk_size(int i);
149 // Get default chunk size (equally divide the space).
150 size_t default_chunk_size();
151 // Adapt the chunk size to follow the allocation rate.
152 size_t adaptive_chunk_size(int i, size_t limit);
153 // Scan and free invalid pages.
154 void scan_pages(size_t page_count);
155 // Return the bottom_region and the top_region. Align them to page_size() boundary.
156 // |------------------new_region---------------------------------|
157 // |----bottom_region--|---intersection---|------top_region------|
158 void select_tails(MemRegion new_region, MemRegion intersection,
159 MemRegion* bottom_region, MemRegion *top_region);
160 // Try to merge the invalid region with the bottom or top region by decreasing
161 // the intersection area. Return the invalid_region aligned to the page_size()
162 // boundary if it's inside the intersection. Return non-empty invalid_region
163 // if it lies inside the intersection (also page-aligned).
164 // |------------------new_region---------------------------------|
165 // |----------------|-------invalid---|--------------------------|
166 // |----bottom_region--|---intersection---|------top_region------|
167 void merge_regions(MemRegion new_region, MemRegion* intersection,
168 MemRegion *invalid_region);
170 public:
171 GrowableArray<LGRPSpace*>* lgrp_spaces() const { return _lgrp_spaces; }
172 MutableNUMASpace();
173 virtual ~MutableNUMASpace();
174 // Space initialization.
175 virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space);
176 // Update space layout if necessary. Do all adaptive resizing job.
177 virtual void update();
178 // Update allocation rate averages.
179 virtual void accumulate_statistics();
181 virtual void clear(bool mangle_space);
182 virtual void mangle_unused_area() PRODUCT_RETURN;
183 virtual void mangle_unused_area_complete() PRODUCT_RETURN;
184 virtual void mangle_region(MemRegion mr) PRODUCT_RETURN;
185 virtual void check_mangled_unused_area(HeapWord* limit) PRODUCT_RETURN;
186 virtual void check_mangled_unused_area_complete() PRODUCT_RETURN;
187 virtual void set_top_for_allocations(HeapWord* v) PRODUCT_RETURN;
188 virtual void set_top_for_allocations() PRODUCT_RETURN;
190 virtual void ensure_parsability();
191 virtual size_t used_in_words() const;
192 virtual size_t free_in_words() const;
193 virtual size_t tlab_capacity(Thread* thr) const;
194 virtual size_t unsafe_max_tlab_alloc(Thread* thr) const;
196 // Allocation (return NULL if full)
197 virtual HeapWord* allocate(size_t word_size);
198 virtual HeapWord* cas_allocate(size_t word_size);
200 // Debugging
201 virtual void print_on(outputStream* st) const;
202 virtual void print_short_on(outputStream* st) const;
203 virtual void verify(bool allow_dirty);
205 virtual void set_top(HeapWord* value);
206 };