8221260: Initialize more class members on construction, remove some unused ones
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0 /*
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2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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23 
24 #include "precompiled.hpp"
25 #include "gc/g1/g1BiasedArray.hpp"
26 #include "gc/g1/g1RegionToSpaceMapper.hpp"
27 #include "logging/log.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "memory/virtualspace.hpp"
30 #include "runtime/java.hpp"
31 #include "runtime/os.inline.hpp"
32 #include "services/memTracker.hpp"
33 #include "utilities/align.hpp"
34 #include "utilities/bitMap.inline.hpp"
35 #include "utilities/formatBuffer.hpp"
36 
37 G1RegionToSpaceMapper::G1RegionToSpaceMapper(ReservedSpace rs,
38                                              size_t used_size,
39                                              size_t page_size,
40                                              size_t region_granularity,
41                                              size_t commit_factor,
42                                              MemoryType type) :
43   _listener(NULL),
44   _storage(rs, used_size, page_size),
45   _region_granularity(region_granularity),
46   _commit_map(rs.size() * commit_factor / region_granularity, mtGC) {
47   guarantee(is_power_of_2(page_size), "must be");
48   guarantee(is_power_of_2(region_granularity), "must be");
49 
50   MemTracker::record_virtual_memory_type((address)rs.base(), type);
51 }
52 
53 // G1RegionToSpaceMapper implementation where the region granularity is larger than
54 // or the same as the commit granularity.
55 // Basically, the space corresponding to one region region spans several OS pages.
56 class G1RegionsLargerThanCommitSizeMapper : public G1RegionToSpaceMapper {
57  private:
58   size_t _pages_per_region;
59 
60  public:
61   G1RegionsLargerThanCommitSizeMapper(ReservedSpace rs,
62                                       size_t actual_size,
63                                       size_t page_size,
64                                       size_t alloc_granularity,
65                                       size_t commit_factor,
66                                       MemoryType type) :
67     G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, commit_factor, type),
68     _pages_per_region(alloc_granularity / (page_size * commit_factor)) {
69 
70     guarantee(alloc_granularity >= page_size, "allocation granularity smaller than commit granularity");
71   }
72 
73   virtual void commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) {
74     size_t const start_page = (size_t)start_idx * _pages_per_region;
75     bool zero_filled = _storage.commit(start_page, num_regions * _pages_per_region);
76     if (AlwaysPreTouch) {
77       _storage.pretouch(start_page, num_regions * _pages_per_region, pretouch_gang);
78     }
79     _commit_map.set_range(start_idx, start_idx + num_regions);
80     fire_on_commit(start_idx, num_regions, zero_filled);
81   }
82 
83   virtual void uncommit_regions(uint start_idx, size_t num_regions) {
84     _storage.uncommit((size_t)start_idx * _pages_per_region, num_regions * _pages_per_region);
85     _commit_map.clear_range(start_idx, start_idx + num_regions);
86   }
87 };
88 
89 // G1RegionToSpaceMapper implementation where the region granularity is smaller
90 // than the commit granularity.
91 // Basically, the contents of one OS page span several regions.
92 class G1RegionsSmallerThanCommitSizeMapper : public G1RegionToSpaceMapper {
93  private:
94   class CommitRefcountArray : public G1BiasedMappedArray<uint> {
95    protected:
96      virtual uint default_value() const { return 0; }
97   };
98 
99   size_t _regions_per_page;
100 
101   CommitRefcountArray _refcounts;
102 
103   uintptr_t region_idx_to_page_idx(uint region) const {
104     return region / _regions_per_page;
105   }
106 
107  public:
108   G1RegionsSmallerThanCommitSizeMapper(ReservedSpace rs,
109                                        size_t actual_size,
110                                        size_t page_size,
111                                        size_t alloc_granularity,
112                                        size_t commit_factor,
113                                        MemoryType type) :
114     G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, commit_factor, type),
115     _regions_per_page((page_size * commit_factor) / alloc_granularity), _refcounts() {
116 
117     guarantee((page_size * commit_factor) >= alloc_granularity, "allocation granularity smaller than commit granularity");
118     _refcounts.initialize((HeapWord*)rs.base(), (HeapWord*)(rs.base() + align_up(rs.size(), page_size)), page_size);
119   }
120 
121   virtual void commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) {
122     size_t const NoPage = ~(size_t)0;
123 
124     size_t first_committed = NoPage;
125     size_t num_committed = 0;
126 
127     bool all_zero_filled = true;
128 
129     for (uint i = start_idx; i < start_idx + num_regions; i++) {
130       assert(!_commit_map.at(i), "Trying to commit storage at region %u that is already committed", i);
131       size_t idx = region_idx_to_page_idx(i);
132       uint old_refcount = _refcounts.get_by_index(idx);
133 
134       bool zero_filled = false;
135       if (old_refcount == 0) {
136         if (first_committed == NoPage) {
137           first_committed = idx;
138           num_committed = 1;
139         } else {
140           num_committed++;
141         }
142         zero_filled = _storage.commit(idx, 1);
143       }
144       all_zero_filled &= zero_filled;
145 
146       _refcounts.set_by_index(idx, old_refcount + 1);
147       _commit_map.set_bit(i);
148     }
149     if (AlwaysPreTouch && num_committed > 0) {
150       _storage.pretouch(first_committed, num_committed, pretouch_gang);
151     }
152     fire_on_commit(start_idx, num_regions, all_zero_filled);
153   }
154 
155   virtual void uncommit_regions(uint start_idx, size_t num_regions) {
156     for (uint i = start_idx; i < start_idx + num_regions; i++) {
157       assert(_commit_map.at(i), "Trying to uncommit storage at region %u that is not committed", i);
158       size_t idx = region_idx_to_page_idx(i);
159       uint old_refcount = _refcounts.get_by_index(idx);
160       assert(old_refcount > 0, "must be");
161       if (old_refcount == 1) {
162         _storage.uncommit(idx, 1);
163       }
164       _refcounts.set_by_index(idx, old_refcount - 1);
165       _commit_map.clear_bit(i);
166     }
167   }
168 };
169 
170 void G1RegionToSpaceMapper::fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled) {
171   if (_listener != NULL) {
172     _listener->on_commit(start_idx, num_regions, zero_filled);
173   }
174 }
175 
176 static bool map_nvdimm_space(ReservedSpace rs) {
177   assert(AllocateOldGenAt != NULL, "");
178   int _backing_fd = os::create_file_for_heap(AllocateOldGenAt);
179   if (_backing_fd == -1) {
180     log_error(gc, init)("Could not create file for Old generation at location %s", AllocateOldGenAt);
181     return false;
182   }
183   // commit this memory in nv-dimm
184   char* ret = os::attempt_reserve_memory_at(rs.size(), rs.base(), _backing_fd);
185 
186   if (ret != rs.base()) {
187     if (ret != NULL) {
188       os::unmap_memory(rs.base(), rs.size());
189     }
190     log_error(gc, init)("Error in mapping Old Gen to given AllocateOldGenAt = %s", AllocateOldGenAt);
191     os::close(_backing_fd);
192     return false;
193   }
194 
195   os::close(_backing_fd);
196   return true;
197 }
198 
199 G1RegionToHeteroSpaceMapper::G1RegionToHeteroSpaceMapper(ReservedSpace rs,
200                                                          size_t actual_size,
201                                                          size_t page_size,
202                                                          size_t alloc_granularity,
203                                                          size_t commit_factor,
204                                                          MemoryType type) :
205   G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, commit_factor, type),
206   _rs(rs),
207   _dram_mapper(NULL),
208   _num_committed_dram(0),
209   _num_committed_nvdimm(0),
210   _start_index_of_dram(0),
211   _page_size(page_size),
212   _commit_factor(commit_factor),
213   _type(type) {
214   assert(actual_size == 2 * MaxHeapSize, "For 2-way heterogenuous heap, reserved space is two times MaxHeapSize");
215 }
216 
217 bool G1RegionToHeteroSpaceMapper::initialize() {
218   // Since we need to re-map the reserved space - 'Xmx' to nv-dimm and 'Xmx' to dram, we need to release the reserved memor
219   // Because on some OSes (e.g. Windows) you cannot do a file mapping on memory reserved with regular mapping.
220   os::release_memory(_rs.base(), _rs.size());
221   // First half of size Xmx is for nv-dimm.
222   ReservedSpace rs_nvdimm = _rs.first_part(MaxHeapSize);
223   assert(rs_nvdimm.base() == _rs.base(), "We should get the same base address");
224 
225   // Second half of reserved memory is mapped to dram.
226   ReservedSpace rs_dram = _rs.last_part(MaxHeapSize);
227 
228   assert(rs_dram.size() == rs_nvdimm.size() && rs_nvdimm.size() == MaxHeapSize, "They all should be same");
229 
230   // Reserve dram memory
231   char* base = os::attempt_reserve_memory_at(rs_dram.size(), rs_dram.base());
232   if (base != rs_dram.base()) {
233     if (base != NULL) {
234       os::release_memory(base, rs_dram.size());
235     }
236     log_error(gc, init)("Error in re-mapping memory on dram during G1 heterogenous memory initialization");
237     return false;
238   }
239 
240   // We reserve and commit this entire space to NV-DIMM.
241   if (!map_nvdimm_space(rs_nvdimm)) {
242     log_error(gc, init)("Error in re-mapping memory to nv-dimm during G1 heterogenous memory initialization");
243     return false;
244   }
245 
246   if (_region_granularity >= (_page_size * _commit_factor)) {
247     _dram_mapper = new G1RegionsLargerThanCommitSizeMapper(rs_dram, rs_dram.size(), _page_size, _region_granularity, _commi
248   } else {
249     _dram_mapper = new G1RegionsSmallerThanCommitSizeMapper(rs_dram, rs_dram.size(), _page_size, _region_granularity, _comm
250   }
251 

252   _start_index_of_dram = (uint)(rs_nvdimm.size() / _region_granularity);
253   return true;
254 }
255 
256 void G1RegionToHeteroSpaceMapper::commit_regions(uint start_idx, size_t num_regions, WorkGang* pretouch_gang) {
257   uint end_idx = (start_idx + (uint)num_regions - 1);
258 
259   uint num_dram = end_idx >= _start_index_of_dram ? MIN2((end_idx - _start_index_of_dram + 1), (uint)num_regions) : 0;
260   uint num_nvdimm = (uint)num_regions - num_dram;
261 
262   if (num_nvdimm > 0) {
263     // We do not need to commit nv-dimm regions, since they are committed in the beginning.
264     _num_committed_nvdimm += num_nvdimm;
265   }
266   if (num_dram > 0) {
267     _dram_mapper->commit_regions(start_idx > _start_index_of_dram ? (start_idx - _start_index_of_dram) : 0, num_dram, preto
268     _num_committed_dram += num_dram;
269   }
270 }
271 
272 void G1RegionToHeteroSpaceMapper::uncommit_regions(uint start_idx, size_t num_regions) {
273   uint end_idx = (start_idx + (uint)num_regions - 1);
274   uint num_dram = end_idx >= _start_index_of_dram ? MIN2((end_idx - _start_index_of_dram + 1), (uint)num_regions) : 0;
275   uint num_nvdimm = (uint)num_regions - num_dram;
276 
277   if (num_nvdimm > 0) {
278     // We do not uncommit memory for nv-dimm regions.
279     _num_committed_nvdimm -= num_nvdimm;
280   }
281 
282   if (num_dram > 0) {
283     _dram_mapper->uncommit_regions(start_idx > _start_index_of_dram ? (start_idx - _start_index_of_dram) : 0, num_dram);
284     _num_committed_dram -= num_dram;
285   }
286 }
287 
288 uint G1RegionToHeteroSpaceMapper::num_committed_dram() const {
289   return _num_committed_dram;
290 }
291 
292 uint G1RegionToHeteroSpaceMapper::num_committed_nvdimm() const {
293   return _num_committed_nvdimm;
294 }
295 
296 G1RegionToSpaceMapper* G1RegionToSpaceMapper::create_heap_mapper(ReservedSpace rs,
297                                                                  size_t actual_size,
298                                                                  size_t page_size,
299                                                                  size_t region_granularity,
300                                                                  size_t commit_factor,
301                                                                  MemoryType type) {
302   if (AllocateOldGenAt != NULL) {
303     G1RegionToHeteroSpaceMapper* mapper = new G1RegionToHeteroSpaceMapper(rs, actual_size, page_size, region_granularity, c
304     if (!mapper->initialize()) {
305       delete mapper;
306       return NULL;
307     }
308     return (G1RegionToSpaceMapper*)mapper;
309   } else {
310     return create_mapper(rs, actual_size, page_size, region_granularity, commit_factor, type);
311   }
312 }
313 
314 G1RegionToSpaceMapper* G1RegionToSpaceMapper::create_mapper(ReservedSpace rs,
315                                                             size_t actual_size,
316                                                             size_t page_size,
317                                                             size_t region_granularity,
318                                                             size_t commit_factor,
319                                                             MemoryType type) {
320   if (region_granularity >= (page_size * commit_factor)) {
321     return new G1RegionsLargerThanCommitSizeMapper(rs, actual_size, page_size, region_granularity, commit_factor, type);
322   } else {
323     return new G1RegionsSmallerThanCommitSizeMapper(rs, actual_size, page_size, region_granularity, commit_factor, type);
324   }
325 }
326 
327 void G1RegionToSpaceMapper::commit_and_set_special() {
328   _storage.commit_and_set_special();
329 }
--- EOF ---