Fri, 25 Oct 2013 15:19:29 -0400
8024927: Nashorn performance regression with CompressedOops
Summary: Allocate compressed class space at end of Java heap. For small heap sizes, without CDS, save some space so compressed classes can have the same favorable compression as oops
Reviewed-by: stefank, hseigel, goetz
1 /*
2 * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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13 * accompanied this code).
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23 */
24 #ifndef SHARE_VM_MEMORY_METASPACE_HPP
25 #define SHARE_VM_MEMORY_METASPACE_HPP
27 #include "memory/allocation.hpp"
28 #include "memory/memRegion.hpp"
29 #include "runtime/virtualspace.hpp"
30 #include "utilities/exceptions.hpp"
32 // Metaspace
33 //
34 // Metaspaces are Arenas for the VM's metadata.
35 // They are allocated one per class loader object, and one for the null
36 // bootstrap class loader
37 // Eventually for bootstrap loader we'll have a read-only section and read-write
38 // to write for DumpSharedSpaces and read for UseSharedSpaces
39 //
40 // block X ---+ +-------------------+
41 // | | Virtualspace |
42 // | | |
43 // | | |
44 // | |-------------------|
45 // | || Chunk |
46 // | || |
47 // | ||---------- |
48 // +------>||| block 0 | |
49 // ||---------- |
50 // ||| block 1 | |
51 // ||---------- |
52 // || |
53 // |-------------------|
54 // | |
55 // | |
56 // +-------------------+
57 //
59 class ChunkManager;
60 class ClassLoaderData;
61 class Metablock;
62 class Metachunk;
63 class MetaWord;
64 class Mutex;
65 class outputStream;
66 class SpaceManager;
67 class VirtualSpaceList;
69 // Metaspaces each have a SpaceManager and allocations
70 // are done by the SpaceManager. Allocations are done
71 // out of the current Metachunk. When the current Metachunk
72 // is exhausted, the SpaceManager gets a new one from
73 // the current VirtualSpace. When the VirtualSpace is exhausted
74 // the SpaceManager gets a new one. The SpaceManager
75 // also manages freelists of available Chunks.
76 //
77 // Currently the space manager maintains the list of
78 // virtual spaces and the list of chunks in use. Its
79 // allocate() method returns a block for use as a
80 // quantum of metadata.
82 class Metaspace : public CHeapObj<mtClass> {
83 friend class VMStructs;
84 friend class SpaceManager;
85 friend class VM_CollectForMetadataAllocation;
86 friend class MetaspaceGC;
87 friend class MetaspaceAux;
89 public:
90 enum MetadataType {
91 ClassType,
92 NonClassType,
93 MetadataTypeCount
94 };
95 enum MetaspaceType {
96 StandardMetaspaceType,
97 BootMetaspaceType,
98 ROMetaspaceType,
99 ReadWriteMetaspaceType,
100 AnonymousMetaspaceType,
101 ReflectionMetaspaceType
102 };
104 private:
105 void initialize(Mutex* lock, MetaspaceType type);
107 // Get the first chunk for a Metaspace. Used for
108 // special cases such as the boot class loader, reflection
109 // class loader and anonymous class loader.
110 Metachunk* get_initialization_chunk(MetadataType mdtype,
111 size_t chunk_word_size,
112 size_t chunk_bunch);
114 // Align up the word size to the allocation word size
115 static size_t align_word_size_up(size_t);
117 // Aligned size of the metaspace.
118 static size_t _compressed_class_space_size;
120 static size_t compressed_class_space_size() {
121 return _compressed_class_space_size;
122 }
123 static void set_compressed_class_space_size(size_t size) {
124 _compressed_class_space_size = size;
125 }
127 static size_t _first_chunk_word_size;
128 static size_t _first_class_chunk_word_size;
130 static size_t _commit_alignment;
131 static size_t _reserve_alignment;
133 SpaceManager* _vsm;
134 SpaceManager* vsm() const { return _vsm; }
136 SpaceManager* _class_vsm;
137 SpaceManager* class_vsm() const { return _class_vsm; }
139 // Allocate space for metadata of type mdtype. This is space
140 // within a Metachunk and is used by
141 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
142 MetaWord* allocate(size_t word_size, MetadataType mdtype);
144 // Virtual Space lists for both classes and other metadata
145 static VirtualSpaceList* _space_list;
146 static VirtualSpaceList* _class_space_list;
148 static ChunkManager* _chunk_manager_metadata;
149 static ChunkManager* _chunk_manager_class;
151 public:
152 static VirtualSpaceList* space_list() { return _space_list; }
153 static VirtualSpaceList* class_space_list() { return _class_space_list; }
154 static VirtualSpaceList* get_space_list(MetadataType mdtype) {
155 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
156 return mdtype == ClassType ? class_space_list() : space_list();
157 }
159 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; }
160 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; }
161 static ChunkManager* get_chunk_manager(MetadataType mdtype) {
162 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
163 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata();
164 }
166 private:
167 // This is used by DumpSharedSpaces only, where only _vsm is used. So we will
168 // maintain a single list for now.
169 void record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size);
171 #ifdef _LP64
172 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);
174 // Returns true if can use CDS with metaspace allocated as specified address.
175 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base);
177 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);
179 static void initialize_class_space(ReservedSpace rs);
180 #endif
182 class AllocRecord : public CHeapObj<mtClass> {
183 public:
184 AllocRecord(address ptr, MetaspaceObj::Type type, int byte_size)
185 : _next(NULL), _ptr(ptr), _type(type), _byte_size(byte_size) {}
186 AllocRecord *_next;
187 address _ptr;
188 MetaspaceObj::Type _type;
189 int _byte_size;
190 };
192 AllocRecord * _alloc_record_head;
193 AllocRecord * _alloc_record_tail;
195 size_t class_chunk_size(size_t word_size);
197 public:
199 Metaspace(Mutex* lock, MetaspaceType type);
200 ~Metaspace();
202 static void ergo_initialize();
203 static void global_initialize();
205 static size_t first_chunk_word_size() { return _first_chunk_word_size; }
206 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
208 static size_t reserve_alignment() { return _reserve_alignment; }
209 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
210 static size_t commit_alignment() { return _commit_alignment; }
211 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; }
213 char* bottom() const;
214 size_t used_words_slow(MetadataType mdtype) const;
215 size_t free_words_slow(MetadataType mdtype) const;
216 size_t capacity_words_slow(MetadataType mdtype) const;
218 size_t used_bytes_slow(MetadataType mdtype) const;
219 size_t capacity_bytes_slow(MetadataType mdtype) const;
221 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
222 bool read_only, MetaspaceObj::Type type, TRAPS);
223 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
225 MetaWord* expand_and_allocate(size_t size,
226 MetadataType mdtype);
228 static bool contains(const void *ptr);
229 void dump(outputStream* const out) const;
231 // Free empty virtualspaces
232 static void purge(MetadataType mdtype);
233 static void purge();
235 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
236 MetadataType mdtype, TRAPS);
238 void print_on(outputStream* st) const;
239 // Debugging support
240 void verify();
242 class AllocRecordClosure : public StackObj {
243 public:
244 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) = 0;
245 };
247 void iterate(AllocRecordClosure *closure);
249 // Return TRUE only if UseCompressedClassPointers is True and DumpSharedSpaces is False.
250 static bool using_class_space() {
251 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers && !DumpSharedSpaces);
252 }
254 static bool is_class_space_allocation(MetadataType mdType) {
255 return mdType == ClassType && using_class_space();
256 }
258 };
260 class MetaspaceAux : AllStatic {
261 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);
263 // These methods iterate over the classloader data graph
264 // for the given Metaspace type. These are slow.
265 static size_t used_bytes_slow(Metaspace::MetadataType mdtype);
266 static size_t free_bytes_slow(Metaspace::MetadataType mdtype);
267 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);
268 static size_t capacity_bytes_slow();
270 // Running sum of space in all Metachunks that has been
271 // allocated to a Metaspace. This is used instead of
272 // iterating over all the classloaders. One for each
273 // type of Metadata
274 static size_t _allocated_capacity_words[Metaspace:: MetadataTypeCount];
275 // Running sum of space in all Metachunks that have
276 // are being used for metadata. One for each
277 // type of Metadata.
278 static size_t _allocated_used_words[Metaspace:: MetadataTypeCount];
280 public:
281 // Decrement and increment _allocated_capacity_words
282 static void dec_capacity(Metaspace::MetadataType type, size_t words);
283 static void inc_capacity(Metaspace::MetadataType type, size_t words);
285 // Decrement and increment _allocated_used_words
286 static void dec_used(Metaspace::MetadataType type, size_t words);
287 static void inc_used(Metaspace::MetadataType type, size_t words);
289 // Total of space allocated to metadata in all Metaspaces.
290 // This sums the space used in each Metachunk by
291 // iterating over the classloader data graph
292 static size_t used_bytes_slow() {
293 return used_bytes_slow(Metaspace::ClassType) +
294 used_bytes_slow(Metaspace::NonClassType);
295 }
297 // Used by MetaspaceCounters
298 static size_t free_chunks_total_words();
299 static size_t free_chunks_total_bytes();
300 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);
302 static size_t allocated_capacity_words(Metaspace::MetadataType mdtype) {
303 return _allocated_capacity_words[mdtype];
304 }
305 static size_t allocated_capacity_words() {
306 return allocated_capacity_words(Metaspace::NonClassType) +
307 allocated_capacity_words(Metaspace::ClassType);
308 }
309 static size_t allocated_capacity_bytes(Metaspace::MetadataType mdtype) {
310 return allocated_capacity_words(mdtype) * BytesPerWord;
311 }
312 static size_t allocated_capacity_bytes() {
313 return allocated_capacity_words() * BytesPerWord;
314 }
316 static size_t allocated_used_words(Metaspace::MetadataType mdtype) {
317 return _allocated_used_words[mdtype];
318 }
319 static size_t allocated_used_words() {
320 return allocated_used_words(Metaspace::NonClassType) +
321 allocated_used_words(Metaspace::ClassType);
322 }
323 static size_t allocated_used_bytes(Metaspace::MetadataType mdtype) {
324 return allocated_used_words(mdtype) * BytesPerWord;
325 }
326 static size_t allocated_used_bytes() {
327 return allocated_used_words() * BytesPerWord;
328 }
330 static size_t free_bytes();
331 static size_t free_bytes(Metaspace::MetadataType mdtype);
333 static size_t reserved_bytes(Metaspace::MetadataType mdtype);
334 static size_t reserved_bytes() {
335 return reserved_bytes(Metaspace::ClassType) +
336 reserved_bytes(Metaspace::NonClassType);
337 }
339 static size_t committed_bytes(Metaspace::MetadataType mdtype);
340 static size_t committed_bytes() {
341 return committed_bytes(Metaspace::ClassType) +
342 committed_bytes(Metaspace::NonClassType);
343 }
345 static size_t min_chunk_size_words();
346 static size_t min_chunk_size_bytes() {
347 return min_chunk_size_words() * BytesPerWord;
348 }
350 // Print change in used metadata.
351 static void print_metaspace_change(size_t prev_metadata_used);
352 static void print_on(outputStream * out);
353 static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
355 static void print_class_waste(outputStream* out);
356 static void print_waste(outputStream* out);
357 static void dump(outputStream* out);
358 static void verify_free_chunks();
359 // Checks that the values returned by allocated_capacity_bytes() and
360 // capacity_bytes_slow() are the same.
361 static void verify_capacity();
362 static void verify_used();
363 static void verify_metrics();
364 };
366 // Metaspace are deallocated when their class loader are GC'ed.
367 // This class implements a policy for inducing GC's to recover
368 // Metaspaces.
370 class MetaspaceGC : AllStatic {
372 // The current high-water-mark for inducing a GC.
373 // When committed memory of all metaspaces reaches this value,
374 // a GC is induced and the value is increased. Size is in bytes.
375 static volatile intptr_t _capacity_until_GC;
377 // For a CMS collection, signal that a concurrent collection should
378 // be started.
379 static bool _should_concurrent_collect;
381 static uint _shrink_factor;
383 static size_t shrink_factor() { return _shrink_factor; }
384 void set_shrink_factor(uint v) { _shrink_factor = v; }
386 public:
388 static void initialize() { _capacity_until_GC = MetaspaceSize; }
390 static size_t capacity_until_GC();
391 static size_t inc_capacity_until_GC(size_t v);
392 static size_t dec_capacity_until_GC(size_t v);
394 static bool should_concurrent_collect() { return _should_concurrent_collect; }
395 static void set_should_concurrent_collect(bool v) {
396 _should_concurrent_collect = v;
397 }
399 // The amount to increase the high-water-mark (_capacity_until_GC)
400 static size_t delta_capacity_until_GC(size_t bytes);
402 // Tells if we have can expand metaspace without hitting set limits.
403 static bool can_expand(size_t words, bool is_class);
405 // Returns amount that we can expand without hitting a GC,
406 // measured in words.
407 static size_t allowed_expansion();
409 // Calculate the new high-water mark at which to induce
410 // a GC.
411 static void compute_new_size();
412 };
414 #endif // SHARE_VM_MEMORY_METASPACE_HPP