summaryrefslogtreecommitdiff
path: root/mm/percpu-internal.h
blob: f9847c1319989e723e651f8d4d14afb9cbe01ea5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _MM_PERCPU_INTERNAL_H
#define _MM_PERCPU_INTERNAL_H

#include <linux/types.h>
#include <linux/percpu.h>
#include <linux/memcontrol.h>

/*
 * pcpu_block_md is the metadata block struct.
 * Each chunk's bitmap is split into a number of full blocks.
 * All units are in terms of bits.
 *
 * The scan hint is the largest known contiguous area before the contig hint.
 * It is not necessarily the actual largest contig hint though.  There is an
 * invariant that the scan_hint_start > contig_hint_start iff
 * scan_hint == contig_hint.  This is necessary because when scanning forward,
 * we don't know if a new contig hint would be better than the current one.
 */
struct pcpu_block_md {
	int			scan_hint;	/* scan hint for block */
	int			scan_hint_start; /* block relative starting
						    position of the scan hint */
	int                     contig_hint;    /* contig hint for block */
	int                     contig_hint_start; /* block relative starting
						      position of the contig hint */
	int                     left_free;      /* size of free space along
						   the left side of the block */
	int                     right_free;     /* size of free space along
						   the right side of the block */
	int                     first_free;     /* block position of first free */
	int			nr_bits;	/* total bits responsible for */
};

struct pcpu_chunk {
#ifdef CONFIG_PERCPU_STATS
	int			nr_alloc;	/* # of allocations */
	size_t			max_alloc_size; /* largest allocation size */
#endif

	struct list_head	list;		/* linked to pcpu_slot lists */
	int			free_bytes;	/* free bytes in the chunk */
	struct pcpu_block_md	chunk_md;
	void			*base_addr;	/* base address of this chunk */

	unsigned long		*alloc_map;	/* allocation map */
	unsigned long		*bound_map;	/* boundary map */
	struct pcpu_block_md	*md_blocks;	/* metadata blocks */

	void			*data;		/* chunk data */
	bool			immutable;	/* no [de]population allowed */
	bool			isolated;	/* isolated from active chunk
						   slots */
	int			start_offset;	/* the overlap with the previous
						   region to have a page aligned
						   base_addr */
	int			end_offset;	/* additional area required to
						   have the region end page
						   aligned */
#ifdef CONFIG_MEMCG_KMEM
	struct obj_cgroup	**obj_cgroups;	/* vector of object cgroups */
#endif

	int			nr_pages;	/* # of pages served by this chunk */
	int			nr_populated;	/* # of populated pages */
	int                     nr_empty_pop_pages; /* # of empty populated pages */
	unsigned long		populated[];	/* populated bitmap */
};

extern spinlock_t pcpu_lock;

extern struct list_head *pcpu_chunk_lists;
extern int pcpu_nr_slots;
extern int pcpu_sidelined_slot;
extern int pcpu_to_depopulate_slot;
extern int pcpu_nr_empty_pop_pages;

extern struct pcpu_chunk *pcpu_first_chunk;
extern struct pcpu_chunk *pcpu_reserved_chunk;

/**
 * pcpu_chunk_nr_blocks - converts nr_pages to # of md_blocks
 * @chunk: chunk of interest
 *
 * This conversion is from the number of physical pages that the chunk
 * serves to the number of bitmap blocks used.
 */
static inline int pcpu_chunk_nr_blocks(struct pcpu_chunk *chunk)
{
	return chunk->nr_pages * PAGE_SIZE / PCPU_BITMAP_BLOCK_SIZE;
}

/**
 * pcpu_nr_pages_to_map_bits - converts the pages to size of bitmap
 * @pages: number of physical pages
 *
 * This conversion is from physical pages to the number of bits
 * required in the bitmap.
 */
static inline int pcpu_nr_pages_to_map_bits(int pages)
{
	return pages * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE;
}

/**
 * pcpu_chunk_map_bits - helper to convert nr_pages to size of bitmap
 * @chunk: chunk of interest
 *
 * This conversion is from the number of physical pages that the chunk
 * serves to the number of bits in the bitmap.
 */
static inline int pcpu_chunk_map_bits(struct pcpu_chunk *chunk)
{
	return pcpu_nr_pages_to_map_bits(chunk->nr_pages);
}

/**
 * pcpu_obj_full_size - helper to calculate size of each accounted object
 * @size: size of area to allocate in bytes
 *
 * For each accounted object there is an extra space which is used to store
 * obj_cgroup membership if kmemcg is not disabled. Charge it too.
 */
static inline size_t pcpu_obj_full_size(size_t size)
{
	size_t extra_size = 0;

#ifdef CONFIG_MEMCG_KMEM
	if (!mem_cgroup_kmem_disabled())
		extra_size += size / PCPU_MIN_ALLOC_SIZE * sizeof(struct obj_cgroup *);
#endif

	return size * num_possible_cpus() + extra_size;
}

#ifdef CONFIG_PERCPU_STATS

#include <linux/spinlock.h>

struct percpu_stats {
	u64 nr_alloc;		/* lifetime # of allocations */
	u64 nr_dealloc;		/* lifetime # of deallocations */
	u64 nr_cur_alloc;	/* current # of allocations */
	u64 nr_max_alloc;	/* max # of live allocations */
	u32 nr_chunks;		/* current # of live chunks */
	u32 nr_max_chunks;	/* max # of live chunks */
	size_t min_alloc_size;	/* min allocation size */
	size_t max_alloc_size;	/* max allocation size */
};

extern struct percpu_stats pcpu_stats;
extern struct pcpu_alloc_info pcpu_stats_ai;

/*
 * For debug purposes. We don't care about the flexible array.
 */
static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
{
	memcpy(&pcpu_stats_ai, ai, sizeof(struct pcpu_alloc_info));

	/* initialize min_alloc_size to unit_size */
	pcpu_stats.min_alloc_size = pcpu_stats_ai.unit_size;
}

/*
 * pcpu_stats_area_alloc - increment area allocation stats
 * @chunk: the location of the area being allocated
 * @size: size of area to allocate in bytes
 *
 * CONTEXT:
 * pcpu_lock.
 */
static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
{
	lockdep_assert_held(&pcpu_lock);

	pcpu_stats.nr_alloc++;
	pcpu_stats.nr_cur_alloc++;
	pcpu_stats.nr_max_alloc =
		max(pcpu_stats.nr_max_alloc, pcpu_stats.nr_cur_alloc);
	pcpu_stats.min_alloc_size =
		min(pcpu_stats.min_alloc_size, size);
	pcpu_stats.max_alloc_size =
		max(pcpu_stats.max_alloc_size, size);

	chunk->nr_alloc++;
	chunk->max_alloc_size = max(chunk->max_alloc_size, size);
}

/*
 * pcpu_stats_area_dealloc - decrement allocation stats
 * @chunk: the location of the area being deallocated
 *
 * CONTEXT:
 * pcpu_lock.
 */
static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
{
	lockdep_assert_held(&pcpu_lock);

	pcpu_stats.nr_dealloc++;
	pcpu_stats.nr_cur_alloc--;

	chunk->nr_alloc--;
}

/*
 * pcpu_stats_chunk_alloc - increment chunk stats
 */
static inline void pcpu_stats_chunk_alloc(void)
{
	unsigned long flags;
	spin_lock_irqsave(&pcpu_lock, flags);

	pcpu_stats.nr_chunks++;
	pcpu_stats.nr_max_chunks =
		max(pcpu_stats.nr_max_chunks, pcpu_stats.nr_chunks);

	spin_unlock_irqrestore(&pcpu_lock, flags);
}

/*
 * pcpu_stats_chunk_dealloc - decrement chunk stats
 */
static inline void pcpu_stats_chunk_dealloc(void)
{
	unsigned long flags;
	spin_lock_irqsave(&pcpu_lock, flags);

	pcpu_stats.nr_chunks--;

	spin_unlock_irqrestore(&pcpu_lock, flags);
}

#else

static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
{
}

static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
{
}

static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
{
}

static inline void pcpu_stats_chunk_alloc(void)
{
}

static inline void pcpu_stats_chunk_dealloc(void)
{
}

#endif /* !CONFIG_PERCPU_STATS */

#endif