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 pcpu_chunk {
36 #ifdef CONFIG_PERCPU_STATS
37 int nr_alloc; /* # of allocations */
38 size_t max_alloc_size; /* largest allocation size */
39 #endif
40
41 struct list_head list; /* linked to pcpu_slot lists */
42 int free_bytes; /* free bytes in the chunk */
43 struct pcpu_block_md chunk_md;
44 unsigned long *bound_map; /* boundary map */
45
46 /*
47 * base_addr is the base address of this chunk.
48 * To reduce false sharing, current layout is optimized to make sure
49 * base_addr locate in the different cacheline with free_bytes and
50 * chunk_md.
51 */
52 void *base_addr ____cacheline_aligned_in_smp;
53
54 unsigned long *alloc_map; /* allocation map */
55 struct pcpu_block_md *md_blocks; /* metadata blocks */
56
57 void *data; /* chunk data */
58 bool immutable; /* no [de]population allowed */
59 bool isolated; /* isolated from active chunk
60 slots */
61 int start_offset; /* the overlap with the previous
62 region to have a page aligned
63 base_addr */
64 int end_offset; /* additional area required to
65 have the region end page
66 aligned */
67 #ifdef CONFIG_MEMCG_KMEM
68 struct obj_cgroup **obj_cgroups; /* vector of object cgroups */
69 #endif
70
71 int nr_pages; /* # of pages served by this chunk */
72 int nr_populated; /* # of populated pages */
73 int nr_empty_pop_pages; /* # of empty populated pages */
74 unsigned long populated[]; /* populated bitmap */
75 };
76
77 extern spinlock_t pcpu_lock;
78
79 extern struct list_head *pcpu_chunk_lists;
80 extern int pcpu_nr_slots;
81 extern int pcpu_sidelined_slot;
82 extern int pcpu_to_depopulate_slot;
83 extern int pcpu_nr_empty_pop_pages;
84
85 extern struct pcpu_chunk *pcpu_first_chunk;
86 extern struct pcpu_chunk *pcpu_reserved_chunk;
87
88 /**
89 * pcpu_chunk_nr_blocks - converts nr_pages to # of md_blocks
90 * @chunk: chunk of interest
91 *
92 * This conversion is from the number of physical pages that the chunk
93 * serves to the number of bitmap blocks used.
94 */
pcpu_chunk_nr_blocks(struct pcpu_chunk * chunk)95 static inline int pcpu_chunk_nr_blocks(struct pcpu_chunk *chunk)
96 {
97 return chunk->nr_pages * PAGE_SIZE / PCPU_BITMAP_BLOCK_SIZE;
98 }
99
100 /**
101 * pcpu_nr_pages_to_map_bits - converts the pages to size of bitmap
102 * @pages: number of physical pages
103 *
104 * This conversion is from physical pages to the number of bits
105 * required in the bitmap.
106 */
pcpu_nr_pages_to_map_bits(int pages)107 static inline int pcpu_nr_pages_to_map_bits(int pages)
108 {
109 return pages * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE;
110 }
111
112 /**
113 * pcpu_chunk_map_bits - helper to convert nr_pages to size of bitmap
114 * @chunk: chunk of interest
115 *
116 * This conversion is from the number of physical pages that the chunk
117 * serves to the number of bits in the bitmap.
118 */
pcpu_chunk_map_bits(struct pcpu_chunk * chunk)119 static inline int pcpu_chunk_map_bits(struct pcpu_chunk *chunk)
120 {
121 return pcpu_nr_pages_to_map_bits(chunk->nr_pages);
122 }
123
124 /**
125 * pcpu_obj_full_size - helper to calculate size of each accounted object
126 * @size: size of area to allocate in bytes
127 *
128 * For each accounted object there is an extra space which is used to store
129 * obj_cgroup membership if kmemcg is not disabled. Charge it too.
130 */
pcpu_obj_full_size(size_t size)131 static inline size_t pcpu_obj_full_size(size_t size)
132 {
133 size_t extra_size = 0;
134
135 #ifdef CONFIG_MEMCG_KMEM
136 if (!mem_cgroup_kmem_disabled())
137 extra_size += size / PCPU_MIN_ALLOC_SIZE * sizeof(struct obj_cgroup *);
138 #endif
139
140 return size * num_possible_cpus() + extra_size;
141 }
142
143 #ifdef CONFIG_PERCPU_STATS
144
145 #include <linux/spinlock.h>
146
147 struct percpu_stats {
148 u64 nr_alloc; /* lifetime # of allocations */
149 u64 nr_dealloc; /* lifetime # of deallocations */
150 u64 nr_cur_alloc; /* current # of allocations */
151 u64 nr_max_alloc; /* max # of live allocations */
152 u32 nr_chunks; /* current # of live chunks */
153 u32 nr_max_chunks; /* max # of live chunks */
154 size_t min_alloc_size; /* min allocation size */
155 size_t max_alloc_size; /* max allocation size */
156 };
157
158 extern struct percpu_stats pcpu_stats;
159 extern struct pcpu_alloc_info pcpu_stats_ai;
160
161 /*
162 * For debug purposes. We don't care about the flexible array.
163 */
pcpu_stats_save_ai(const struct pcpu_alloc_info * ai)164 static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
165 {
166 memcpy(&pcpu_stats_ai, ai, sizeof(struct pcpu_alloc_info));
167
168 /* initialize min_alloc_size to unit_size */
169 pcpu_stats.min_alloc_size = pcpu_stats_ai.unit_size;
170 }
171
172 /*
173 * pcpu_stats_area_alloc - increment area allocation stats
174 * @chunk: the location of the area being allocated
175 * @size: size of area to allocate in bytes
176 *
177 * CONTEXT:
178 * pcpu_lock.
179 */
pcpu_stats_area_alloc(struct pcpu_chunk * chunk,size_t size)180 static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
181 {
182 lockdep_assert_held(&pcpu_lock);
183
184 pcpu_stats.nr_alloc++;
185 pcpu_stats.nr_cur_alloc++;
186 pcpu_stats.nr_max_alloc =
187 max(pcpu_stats.nr_max_alloc, pcpu_stats.nr_cur_alloc);
188 pcpu_stats.min_alloc_size =
189 min(pcpu_stats.min_alloc_size, size);
190 pcpu_stats.max_alloc_size =
191 max(pcpu_stats.max_alloc_size, size);
192
193 chunk->nr_alloc++;
194 chunk->max_alloc_size = max(chunk->max_alloc_size, size);
195 }
196
197 /*
198 * pcpu_stats_area_dealloc - decrement allocation stats
199 * @chunk: the location of the area being deallocated
200 *
201 * CONTEXT:
202 * pcpu_lock.
203 */
pcpu_stats_area_dealloc(struct pcpu_chunk * chunk)204 static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
205 {
206 lockdep_assert_held(&pcpu_lock);
207
208 pcpu_stats.nr_dealloc++;
209 pcpu_stats.nr_cur_alloc--;
210
211 chunk->nr_alloc--;
212 }
213
214 /*
215 * pcpu_stats_chunk_alloc - increment chunk stats
216 */
pcpu_stats_chunk_alloc(void)217 static inline void pcpu_stats_chunk_alloc(void)
218 {
219 unsigned long flags;
220 spin_lock_irqsave(&pcpu_lock, flags);
221
222 pcpu_stats.nr_chunks++;
223 pcpu_stats.nr_max_chunks =
224 max(pcpu_stats.nr_max_chunks, pcpu_stats.nr_chunks);
225
226 spin_unlock_irqrestore(&pcpu_lock, flags);
227 }
228
229 /*
230 * pcpu_stats_chunk_dealloc - decrement chunk stats
231 */
pcpu_stats_chunk_dealloc(void)232 static inline void pcpu_stats_chunk_dealloc(void)
233 {
234 unsigned long flags;
235 spin_lock_irqsave(&pcpu_lock, flags);
236
237 pcpu_stats.nr_chunks--;
238
239 spin_unlock_irqrestore(&pcpu_lock, flags);
240 }
241
242 #else
243
pcpu_stats_save_ai(const struct pcpu_alloc_info * ai)244 static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
245 {
246 }
247
pcpu_stats_area_alloc(struct pcpu_chunk * chunk,size_t size)248 static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
249 {
250 }
251
pcpu_stats_area_dealloc(struct pcpu_chunk * chunk)252 static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
253 {
254 }
255
pcpu_stats_chunk_alloc(void)256 static inline void pcpu_stats_chunk_alloc(void)
257 {
258 }
259
pcpu_stats_chunk_dealloc(void)260 static inline void pcpu_stats_chunk_dealloc(void)
261 {
262 }
263
264 #endif /* !CONFIG_PERCPU_STATS */
265
266 #endif
267