mm/percpu-internal.h

   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