1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _MM_PERCPU_INTERNAL_H
3 #define _MM_PERCPU_INTERNAL_H
4
5 #include <linux/types.h>
6 #include <linux/percpu.h>
7 #include <linux/memcontrol.h>
8
9 /*
10 * pcpu_block_md is the metadata block struct.
11 * Each chunk's bitmap is split into a number of full blocks.
12 * All units are in terms of bits.
13 *
14 * The scan hint is the largest known contiguous area before the contig hint.
15 * It is not necessarily the actual largest contig hint though. There is an
16 * invariant that the scan_hint_start > contig_hint_start iff
17 * scan_hint == contig_hint. This is necessary because when scanning forward,
18 * we don't know if a new contig hint would be better than the current one.
19 */
20 struct pcpu_block_md {
21 int scan_hint; /* scan hint for block */
22 int scan_hint_start; /* block relative starting
23 position of the scan hint */
24 int contig_hint; /* contig hint for block */
25 int contig_hint_start; /* block relative starting
26 position of the contig hint */
27 int left_free; /* size of free space along
28 the left side of the block */
29 int right_free; /* size of free space along
30 the right side of the block */
31 int first_free; /* block position of first free */
32 int nr_bits; /* total bits responsible for */
33 };
34
35 struct pcpuobj_ext {
36 #ifdef CONFIG_MEMCG
37 struct obj_cgroup *cgroup;
38 #endif
39 #ifdef CONFIG_MEM_ALLOC_PROFILING
40 union codetag_ref tag;
41 #endif
42 };
43
44 #if defined(CONFIG_MEMCG) || defined(CONFIG_MEM_ALLOC_PROFILING)
45 #define NEED_PCPUOBJ_EXT
46 #endif
47
48 struct pcpu_chunk {
49 #ifdef CONFIG_PERCPU_STATS
50 int nr_alloc; /* # of allocations */
51 size_t max_alloc_size; /* largest allocation size */
52 #endif
53
54 struct list_head list; /* linked to pcpu_slot lists */
55 int free_bytes; /* free bytes in the chunk */
56 struct pcpu_block_md chunk_md;
57 unsigned long *bound_map; /* boundary map */
58
59 /*
60 * base_addr is the base address of this chunk.
61 * To reduce false sharing, current layout is optimized to make sure
62 * base_addr locate in the different cacheline with free_bytes and
63 * chunk_md.
64 */
65 void *base_addr ____cacheline_aligned_in_smp;
66
67 unsigned long *alloc_map; /* allocation map */
68 struct pcpu_block_md *md_blocks; /* metadata blocks */
69
70 void *data; /* chunk data */
71 bool immutable; /* no [de]population allowed */
72 bool isolated; /* isolated from active chunk
73 slots */
74 int start_offset; /* the overlap with the previous
75 region to have a page aligned
76 base_addr */
77 int end_offset; /* additional area required to
78 have the region end page
79 aligned */
80 #ifdef NEED_PCPUOBJ_EXT
81 struct pcpuobj_ext *obj_exts; /* vector of object cgroups */
82 #endif
83
84 int nr_pages; /* # of pages served by this chunk */
85 int nr_populated; /* # of populated pages */
86 int nr_empty_pop_pages; /* # of empty populated pages */
87 unsigned long populated[]; /* populated bitmap */
88 };
89
90 static inline bool need_pcpuobj_ext(void)
91 {
92 if (IS_ENABLED(CONFIG_MEM_ALLOC_PROFILING))
93 return true;
94 if (!mem_cgroup_kmem_disabled())
95 return true;
96 return false;
97 }
98
99 extern spinlock_t pcpu_lock;
100
101 extern struct list_head *pcpu_chunk_lists;
102 extern int pcpu_nr_slots;
103 extern int pcpu_sidelined_slot;
104 extern int pcpu_to_depopulate_slot;
105 extern int pcpu_nr_empty_pop_pages;
106
107 extern struct pcpu_chunk *pcpu_first_chunk;
108 extern struct pcpu_chunk *pcpu_reserved_chunk;
109
110 /**
111 * pcpu_chunk_nr_blocks - converts nr_pages to # of md_blocks
112 * @chunk: chunk of interest
113 *
114 * This conversion is from the number of physical pages that the chunk
115 * serves to the number of bitmap blocks used.
116 */
117 static inline int pcpu_chunk_nr_blocks(struct pcpu_chunk *chunk)
118 {
119 return chunk->nr_pages * PAGE_SIZE / PCPU_BITMAP_BLOCK_SIZE;
120 }
121
122 /**
123 * pcpu_nr_pages_to_map_bits - converts the pages to size of bitmap
124 * @pages: number of physical pages
125 *
126 * This conversion is from physical pages to the number of bits
127 * required in the bitmap.
128 */
129 static inline int pcpu_nr_pages_to_map_bits(int pages)
130 {
131 return pages * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE;
132 }
133
134 /**
135 * pcpu_chunk_map_bits - helper to convert nr_pages to size of bitmap
136 * @chunk: chunk of interest
137 *
138 * This conversion is from the number of physical pages that the chunk
139 * serves to the number of bits in the bitmap.
140 */
141 static inline int pcpu_chunk_map_bits(struct pcpu_chunk *chunk)
142 {
143 return pcpu_nr_pages_to_map_bits(chunk->nr_pages);
144 }
145
146 /**
147 * pcpu_obj_full_size - helper to calculate size of each accounted object
148 * @size: size of area to allocate in bytes
149 *
150 * For each accounted object there is an extra space which is used to store
151 * obj_cgroup membership if kmemcg is not disabled. Charge it too.
152 */
153 static inline size_t pcpu_obj_full_size(size_t size)
154 {
155 size_t extra_size = 0;
156
157 #ifdef CONFIG_MEMCG
158 if (!mem_cgroup_kmem_disabled())
159 extra_size += size / PCPU_MIN_ALLOC_SIZE * sizeof(struct obj_cgroup *);
160 #endif
161
162 return size * num_possible_cpus() + extra_size;
163 }
164
165 #ifdef CONFIG_PERCPU_STATS
166
167 #include <linux/spinlock.h>
168
169 struct percpu_stats {
170 u64 nr_alloc; /* lifetime # of allocations */
171 u64 nr_dealloc; /* lifetime # of deallocations */
172 u64 nr_cur_alloc; /* current # of allocations */
173 u64 nr_max_alloc; /* max # of live allocations */
174 u32 nr_chunks; /* current # of live chunks */
175 u32 nr_max_chunks; /* max # of live chunks */
176 size_t min_alloc_size; /* min allocation size */
177 size_t max_alloc_size; /* max allocation size */
178 };
179
180 extern struct percpu_stats pcpu_stats;
181 extern struct pcpu_alloc_info pcpu_stats_ai;
182
183 /*
184 * For debug purposes. We don't care about the flexible array.
185 */
186 static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
187 {
188 memcpy(&pcpu_stats_ai, ai, sizeof(struct pcpu_alloc_info));
189
190 /* initialize min_alloc_size to unit_size */
191 pcpu_stats.min_alloc_size = pcpu_stats_ai.unit_size;
192 }
193
194 /*
195 * pcpu_stats_area_alloc - increment area allocation stats
196 * @chunk: the location of the area being allocated
197 * @size: size of area to allocate in bytes
198 *
199 * CONTEXT:
200 * pcpu_lock.
201 */
202 static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
203 {
204 lockdep_assert_held(&pcpu_lock);
205
206 pcpu_stats.nr_alloc++;
207 pcpu_stats.nr_cur_alloc++;
208 pcpu_stats.nr_max_alloc =
209 max(pcpu_stats.nr_max_alloc, pcpu_stats.nr_cur_alloc);
210 pcpu_stats.min_alloc_size =
211 min(pcpu_stats.min_alloc_size, size);
212 pcpu_stats.max_alloc_size =
213 max(pcpu_stats.max_alloc_size, size);
214
215 chunk->nr_alloc++;
216 chunk->max_alloc_size = max(chunk->max_alloc_size, size);
217 }
218
219 /*
220 * pcpu_stats_area_dealloc - decrement allocation stats
221 * @chunk: the location of the area being deallocated
222 *
223 * CONTEXT:
224 * pcpu_lock.
225 */
226 static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
227 {
228 lockdep_assert_held(&pcpu_lock);
229
230 pcpu_stats.nr_dealloc++;
231 pcpu_stats.nr_cur_alloc--;
232
233 chunk->nr_alloc--;
234 }
235
236 /*
237 * pcpu_stats_chunk_alloc - increment chunk stats
238 */
239 static inline void pcpu_stats_chunk_alloc(void)
240 {
241 unsigned long flags;
242 spin_lock_irqsave(&pcpu_lock, flags);
243
244 pcpu_stats.nr_chunks++;
245 pcpu_stats.nr_max_chunks =
246 max(pcpu_stats.nr_max_chunks, pcpu_stats.nr_chunks);
247
248 spin_unlock_irqrestore(&pcpu_lock, flags);
249 }
250
251 /*
252 * pcpu_stats_chunk_dealloc - decrement chunk stats
253 */
254 static inline void pcpu_stats_chunk_dealloc(void)
255 {
256 unsigned long flags;
257 spin_lock_irqsave(&pcpu_lock, flags);
258
259 pcpu_stats.nr_chunks--;
260
261 spin_unlock_irqrestore(&pcpu_lock, flags);
262 }
263
264 #else
265
266 static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
267 {
268 }
269
270 static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
271 {
272 }
273
274 static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
275 {
276 }
277
278 static inline void pcpu_stats_chunk_alloc(void)
279 {
280 }
281
282 static inline void pcpu_stats_chunk_dealloc(void)
283 {
284 }
285
286 #endif /* !CONFIG_PERCPU_STATS */
287
288 #endif
289
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