Thomas Gleixner | 0fc479b | 2019-05-29 16:57:42 -0700 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (C) 2016 Facebook |
| 4 | * Copyright (C) 2013-2014 Jens Axboe |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 5 | */ |
| 6 | |
Ingo Molnar | af8601a | 2017-02-03 09:57:00 +0100 | [diff] [blame] | 7 | #include <linux/sched.h> |
Omar Sandoval | 98d9541 | 2016-09-17 01:28:25 -0700 | [diff] [blame] | 8 | #include <linux/random.h> |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 9 | #include <linux/sbitmap.h> |
Omar Sandoval | 24af1ccf | 2017-01-25 14:32:13 -0800 | [diff] [blame] | 10 | #include <linux/seq_file.h> |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 11 | |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 12 | static int init_alloc_hint(struct sbitmap *sb, gfp_t flags) |
Ming Lei | bf2c428 | 2021-01-22 10:33:07 +0800 | [diff] [blame] | 13 | { |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 14 | unsigned depth = sb->depth; |
Ming Lei | bf2c428 | 2021-01-22 10:33:07 +0800 | [diff] [blame] | 15 | |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 16 | sb->alloc_hint = alloc_percpu_gfp(unsigned int, flags); |
| 17 | if (!sb->alloc_hint) |
Ming Lei | bf2c428 | 2021-01-22 10:33:07 +0800 | [diff] [blame] | 18 | return -ENOMEM; |
| 19 | |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 20 | if (depth && !sb->round_robin) { |
Ming Lei | bf2c428 | 2021-01-22 10:33:07 +0800 | [diff] [blame] | 21 | int i; |
| 22 | |
| 23 | for_each_possible_cpu(i) |
Jason A. Donenfeld | 8032bf1 | 2022-10-09 20:44:02 -0600 | [diff] [blame] | 24 | *per_cpu_ptr(sb->alloc_hint, i) = get_random_u32_below(depth); |
Ming Lei | bf2c428 | 2021-01-22 10:33:07 +0800 | [diff] [blame] | 25 | } |
Ming Lei | bf2c428 | 2021-01-22 10:33:07 +0800 | [diff] [blame] | 26 | return 0; |
| 27 | } |
| 28 | |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 29 | static inline unsigned update_alloc_hint_before_get(struct sbitmap *sb, |
Ming Lei | bf2c428 | 2021-01-22 10:33:07 +0800 | [diff] [blame] | 30 | unsigned int depth) |
| 31 | { |
| 32 | unsigned hint; |
| 33 | |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 34 | hint = this_cpu_read(*sb->alloc_hint); |
Ming Lei | bf2c428 | 2021-01-22 10:33:07 +0800 | [diff] [blame] | 35 | if (unlikely(hint >= depth)) { |
Jason A. Donenfeld | 8032bf1 | 2022-10-09 20:44:02 -0600 | [diff] [blame] | 36 | hint = depth ? get_random_u32_below(depth) : 0; |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 37 | this_cpu_write(*sb->alloc_hint, hint); |
Ming Lei | bf2c428 | 2021-01-22 10:33:07 +0800 | [diff] [blame] | 38 | } |
| 39 | |
| 40 | return hint; |
| 41 | } |
| 42 | |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 43 | static inline void update_alloc_hint_after_get(struct sbitmap *sb, |
Ming Lei | bf2c428 | 2021-01-22 10:33:07 +0800 | [diff] [blame] | 44 | unsigned int depth, |
| 45 | unsigned int hint, |
| 46 | unsigned int nr) |
| 47 | { |
| 48 | if (nr == -1) { |
| 49 | /* If the map is full, a hint won't do us much good. */ |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 50 | this_cpu_write(*sb->alloc_hint, 0); |
| 51 | } else if (nr == hint || unlikely(sb->round_robin)) { |
Ming Lei | bf2c428 | 2021-01-22 10:33:07 +0800 | [diff] [blame] | 52 | /* Only update the hint if we used it. */ |
| 53 | hint = nr + 1; |
| 54 | if (hint >= depth - 1) |
| 55 | hint = 0; |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 56 | this_cpu_write(*sb->alloc_hint, hint); |
Ming Lei | bf2c428 | 2021-01-22 10:33:07 +0800 | [diff] [blame] | 57 | } |
| 58 | } |
| 59 | |
Jens Axboe | b2dbff1 | 2018-12-11 18:39:41 -0700 | [diff] [blame] | 60 | /* |
| 61 | * See if we have deferred clears that we can batch move |
| 62 | */ |
Pavel Begunkov | b78beea | 2020-11-22 15:35:45 +0000 | [diff] [blame] | 63 | static inline bool sbitmap_deferred_clear(struct sbitmap_word *map) |
Jens Axboe | b2dbff1 | 2018-12-11 18:39:41 -0700 | [diff] [blame] | 64 | { |
Pavel Begunkov | c3250c8 | 2020-11-22 15:35:47 +0000 | [diff] [blame] | 65 | unsigned long mask; |
Jens Axboe | b2dbff1 | 2018-12-11 18:39:41 -0700 | [diff] [blame] | 66 | |
Pavel Begunkov | 661d4f5 | 2020-11-22 15:35:46 +0000 | [diff] [blame] | 67 | if (!READ_ONCE(map->cleared)) |
| 68 | return false; |
Jens Axboe | b2dbff1 | 2018-12-11 18:39:41 -0700 | [diff] [blame] | 69 | |
| 70 | /* |
| 71 | * First get a stable cleared mask, setting the old mask to 0. |
| 72 | */ |
Pavel Begunkov | b78beea | 2020-11-22 15:35:45 +0000 | [diff] [blame] | 73 | mask = xchg(&map->cleared, 0); |
Jens Axboe | b2dbff1 | 2018-12-11 18:39:41 -0700 | [diff] [blame] | 74 | |
| 75 | /* |
| 76 | * Now clear the masked bits in our free word |
| 77 | */ |
Pavel Begunkov | c3250c8 | 2020-11-22 15:35:47 +0000 | [diff] [blame] | 78 | atomic_long_andnot(mask, (atomic_long_t *)&map->word); |
| 79 | BUILD_BUG_ON(sizeof(atomic_long_t) != sizeof(map->word)); |
Pavel Begunkov | 661d4f5 | 2020-11-22 15:35:46 +0000 | [diff] [blame] | 80 | return true; |
Jens Axboe | b2dbff1 | 2018-12-11 18:39:41 -0700 | [diff] [blame] | 81 | } |
| 82 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 83 | int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift, |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 84 | gfp_t flags, int node, bool round_robin, |
| 85 | bool alloc_hint) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 86 | { |
| 87 | unsigned int bits_per_word; |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 88 | |
Ming Lei | 2d13b1e | 2021-01-22 10:33:10 +0800 | [diff] [blame] | 89 | if (shift < 0) |
| 90 | shift = sbitmap_calculate_shift(depth); |
| 91 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 92 | bits_per_word = 1U << shift; |
| 93 | if (bits_per_word > BITS_PER_LONG) |
| 94 | return -EINVAL; |
| 95 | |
| 96 | sb->shift = shift; |
| 97 | sb->depth = depth; |
| 98 | sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word); |
Ming Lei | efe1f3a | 2021-01-22 10:33:06 +0800 | [diff] [blame] | 99 | sb->round_robin = round_robin; |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 100 | |
| 101 | if (depth == 0) { |
| 102 | sb->map = NULL; |
| 103 | return 0; |
| 104 | } |
| 105 | |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 106 | if (alloc_hint) { |
| 107 | if (init_alloc_hint(sb, flags)) |
| 108 | return -ENOMEM; |
| 109 | } else { |
| 110 | sb->alloc_hint = NULL; |
| 111 | } |
| 112 | |
Ming Lei | 863a66c | 2022-03-16 09:27:08 +0800 | [diff] [blame] | 113 | sb->map = kvzalloc_node(sb->map_nr * sizeof(*sb->map), flags, node); |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 114 | if (!sb->map) { |
| 115 | free_percpu(sb->alloc_hint); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 116 | return -ENOMEM; |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 117 | } |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 118 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 119 | return 0; |
| 120 | } |
| 121 | EXPORT_SYMBOL_GPL(sbitmap_init_node); |
| 122 | |
| 123 | void sbitmap_resize(struct sbitmap *sb, unsigned int depth) |
| 124 | { |
| 125 | unsigned int bits_per_word = 1U << sb->shift; |
| 126 | unsigned int i; |
| 127 | |
Jens Axboe | b2dbff1 | 2018-12-11 18:39:41 -0700 | [diff] [blame] | 128 | for (i = 0; i < sb->map_nr; i++) |
Pavel Begunkov | b78beea | 2020-11-22 15:35:45 +0000 | [diff] [blame] | 129 | sbitmap_deferred_clear(&sb->map[i]); |
Jens Axboe | b2dbff1 | 2018-12-11 18:39:41 -0700 | [diff] [blame] | 130 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 131 | sb->depth = depth; |
| 132 | sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 133 | } |
| 134 | EXPORT_SYMBOL_GPL(sbitmap_resize); |
| 135 | |
Omar Sandoval | c05e667 | 2017-04-14 00:59:58 -0700 | [diff] [blame] | 136 | static int __sbitmap_get_word(unsigned long *word, unsigned long depth, |
| 137 | unsigned int hint, bool wrap) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 138 | { |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 139 | int nr; |
| 140 | |
Pavel Begunkov | 0eff1f1 | 2020-11-22 15:35:48 +0000 | [diff] [blame] | 141 | /* don't wrap if starting from 0 */ |
| 142 | wrap = wrap && hint; |
| 143 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 144 | while (1) { |
Omar Sandoval | c05e667 | 2017-04-14 00:59:58 -0700 | [diff] [blame] | 145 | nr = find_next_zero_bit(word, depth, hint); |
| 146 | if (unlikely(nr >= depth)) { |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 147 | /* |
| 148 | * We started with an offset, and we didn't reset the |
| 149 | * offset to 0 in a failure case, so start from 0 to |
| 150 | * exhaust the map. |
| 151 | */ |
Pavel Begunkov | 0eff1f1 | 2020-11-22 15:35:48 +0000 | [diff] [blame] | 152 | if (hint && wrap) { |
| 153 | hint = 0; |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 154 | continue; |
| 155 | } |
| 156 | return -1; |
| 157 | } |
| 158 | |
Omar Sandoval | 4ace53f | 2018-02-27 16:56:43 -0800 | [diff] [blame] | 159 | if (!test_and_set_bit_lock(nr, word)) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 160 | break; |
| 161 | |
| 162 | hint = nr + 1; |
Omar Sandoval | c05e667 | 2017-04-14 00:59:58 -0700 | [diff] [blame] | 163 | if (hint >= depth - 1) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 164 | hint = 0; |
| 165 | } |
| 166 | |
| 167 | return nr; |
| 168 | } |
| 169 | |
Kemeng Shi | 08470a9 | 2023-01-17 04:50:57 +0800 | [diff] [blame] | 170 | static int sbitmap_find_bit_in_word(struct sbitmap_word *map, |
| 171 | unsigned int depth, |
| 172 | unsigned int alloc_hint, |
| 173 | bool wrap) |
Jens Axboe | ea86ea2 | 2018-11-30 13:18:06 -0700 | [diff] [blame] | 174 | { |
| 175 | int nr; |
| 176 | |
| 177 | do { |
Kemeng Shi | 08470a9 | 2023-01-17 04:50:57 +0800 | [diff] [blame] | 178 | nr = __sbitmap_get_word(&map->word, depth, |
| 179 | alloc_hint, wrap); |
Jens Axboe | ea86ea2 | 2018-11-30 13:18:06 -0700 | [diff] [blame] | 180 | if (nr != -1) |
| 181 | break; |
Pavel Begunkov | b78beea | 2020-11-22 15:35:45 +0000 | [diff] [blame] | 182 | if (!sbitmap_deferred_clear(map)) |
Jens Axboe | ea86ea2 | 2018-11-30 13:18:06 -0700 | [diff] [blame] | 183 | break; |
| 184 | } while (1); |
| 185 | |
| 186 | return nr; |
| 187 | } |
| 188 | |
Kemeng Shi | 678418c | 2023-01-17 04:50:58 +0800 | [diff] [blame] | 189 | static int sbitmap_find_bit(struct sbitmap *sb, |
| 190 | unsigned int depth, |
| 191 | unsigned int index, |
| 192 | unsigned int alloc_hint, |
| 193 | bool wrap) |
| 194 | { |
| 195 | unsigned int i; |
| 196 | int nr = -1; |
| 197 | |
| 198 | for (i = 0; i < sb->map_nr; i++) { |
| 199 | nr = sbitmap_find_bit_in_word(&sb->map[index], |
| 200 | min_t(unsigned int, |
| 201 | __map_depth(sb, index), |
| 202 | depth), |
| 203 | alloc_hint, wrap); |
| 204 | |
| 205 | if (nr != -1) { |
| 206 | nr += index << sb->shift; |
| 207 | break; |
| 208 | } |
| 209 | |
| 210 | /* Jump to next index. */ |
| 211 | alloc_hint = 0; |
| 212 | if (++index >= sb->map_nr) |
| 213 | index = 0; |
| 214 | } |
| 215 | |
| 216 | return nr; |
| 217 | } |
| 218 | |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 219 | static int __sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 220 | { |
Kemeng Shi | 678418c | 2023-01-17 04:50:58 +0800 | [diff] [blame] | 221 | unsigned int index; |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 222 | |
| 223 | index = SB_NR_TO_INDEX(sb, alloc_hint); |
| 224 | |
Jens Axboe | 27fae42 | 2018-11-29 12:35:16 -0700 | [diff] [blame] | 225 | /* |
| 226 | * Unless we're doing round robin tag allocation, just use the |
| 227 | * alloc_hint to find the right word index. No point in looping |
| 228 | * twice in find_next_zero_bit() for that case. |
| 229 | */ |
Ming Lei | efe1f3a | 2021-01-22 10:33:06 +0800 | [diff] [blame] | 230 | if (sb->round_robin) |
Jens Axboe | 27fae42 | 2018-11-29 12:35:16 -0700 | [diff] [blame] | 231 | alloc_hint = SB_NR_TO_BIT(sb, alloc_hint); |
| 232 | else |
| 233 | alloc_hint = 0; |
| 234 | |
Kemeng Shi | 678418c | 2023-01-17 04:50:58 +0800 | [diff] [blame] | 235 | return sbitmap_find_bit(sb, UINT_MAX, index, alloc_hint, |
| 236 | !sb->round_robin); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 237 | } |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 238 | |
| 239 | int sbitmap_get(struct sbitmap *sb) |
| 240 | { |
| 241 | int nr; |
| 242 | unsigned int hint, depth; |
| 243 | |
| 244 | if (WARN_ON_ONCE(unlikely(!sb->alloc_hint))) |
| 245 | return -1; |
| 246 | |
| 247 | depth = READ_ONCE(sb->depth); |
| 248 | hint = update_alloc_hint_before_get(sb, depth); |
| 249 | nr = __sbitmap_get(sb, hint); |
| 250 | update_alloc_hint_after_get(sb, depth, hint, nr); |
| 251 | |
| 252 | return nr; |
| 253 | } |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 254 | EXPORT_SYMBOL_GPL(sbitmap_get); |
| 255 | |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 256 | static int __sbitmap_get_shallow(struct sbitmap *sb, |
| 257 | unsigned int alloc_hint, |
| 258 | unsigned long shallow_depth) |
Omar Sandoval | c05e667 | 2017-04-14 00:59:58 -0700 | [diff] [blame] | 259 | { |
Kemeng Shi | 678418c | 2023-01-17 04:50:58 +0800 | [diff] [blame] | 260 | unsigned int index; |
Omar Sandoval | c05e667 | 2017-04-14 00:59:58 -0700 | [diff] [blame] | 261 | |
| 262 | index = SB_NR_TO_INDEX(sb, alloc_hint); |
Kemeng Shi | f1591a8 | 2023-01-17 04:50:55 +0800 | [diff] [blame] | 263 | alloc_hint = SB_NR_TO_BIT(sb, alloc_hint); |
Omar Sandoval | c05e667 | 2017-04-14 00:59:58 -0700 | [diff] [blame] | 264 | |
Kemeng Shi | 678418c | 2023-01-17 04:50:58 +0800 | [diff] [blame] | 265 | return sbitmap_find_bit(sb, shallow_depth, index, alloc_hint, true); |
Omar Sandoval | c05e667 | 2017-04-14 00:59:58 -0700 | [diff] [blame] | 266 | } |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 267 | |
| 268 | int sbitmap_get_shallow(struct sbitmap *sb, unsigned long shallow_depth) |
| 269 | { |
| 270 | int nr; |
| 271 | unsigned int hint, depth; |
| 272 | |
| 273 | if (WARN_ON_ONCE(unlikely(!sb->alloc_hint))) |
| 274 | return -1; |
| 275 | |
| 276 | depth = READ_ONCE(sb->depth); |
| 277 | hint = update_alloc_hint_before_get(sb, depth); |
| 278 | nr = __sbitmap_get_shallow(sb, hint, shallow_depth); |
| 279 | update_alloc_hint_after_get(sb, depth, hint, nr); |
| 280 | |
| 281 | return nr; |
| 282 | } |
Omar Sandoval | c05e667 | 2017-04-14 00:59:58 -0700 | [diff] [blame] | 283 | EXPORT_SYMBOL_GPL(sbitmap_get_shallow); |
| 284 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 285 | bool sbitmap_any_bit_set(const struct sbitmap *sb) |
| 286 | { |
| 287 | unsigned int i; |
| 288 | |
| 289 | for (i = 0; i < sb->map_nr; i++) { |
Jens Axboe | b2dbff1 | 2018-12-11 18:39:41 -0700 | [diff] [blame] | 290 | if (sb->map[i].word & ~sb->map[i].cleared) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 291 | return true; |
| 292 | } |
| 293 | return false; |
| 294 | } |
| 295 | EXPORT_SYMBOL_GPL(sbitmap_any_bit_set); |
| 296 | |
Jens Axboe | ea86ea2 | 2018-11-30 13:18:06 -0700 | [diff] [blame] | 297 | static unsigned int __sbitmap_weight(const struct sbitmap *sb, bool set) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 298 | { |
Colin Ian King | 60658e0 | 2016-09-19 14:34:08 +0100 | [diff] [blame] | 299 | unsigned int i, weight = 0; |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 300 | |
| 301 | for (i = 0; i < sb->map_nr; i++) { |
| 302 | const struct sbitmap_word *word = &sb->map[i]; |
Ming Lei | 3301bc5 | 2022-01-10 15:29:45 +0800 | [diff] [blame] | 303 | unsigned int word_depth = __map_depth(sb, i); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 304 | |
Jens Axboe | ea86ea2 | 2018-11-30 13:18:06 -0700 | [diff] [blame] | 305 | if (set) |
Ming Lei | 3301bc5 | 2022-01-10 15:29:45 +0800 | [diff] [blame] | 306 | weight += bitmap_weight(&word->word, word_depth); |
Jens Axboe | ea86ea2 | 2018-11-30 13:18:06 -0700 | [diff] [blame] | 307 | else |
Ming Lei | 3301bc5 | 2022-01-10 15:29:45 +0800 | [diff] [blame] | 308 | weight += bitmap_weight(&word->cleared, word_depth); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 309 | } |
| 310 | return weight; |
| 311 | } |
Jens Axboe | ea86ea2 | 2018-11-30 13:18:06 -0700 | [diff] [blame] | 312 | |
Jens Axboe | ea86ea2 | 2018-11-30 13:18:06 -0700 | [diff] [blame] | 313 | static unsigned int sbitmap_cleared(const struct sbitmap *sb) |
| 314 | { |
| 315 | return __sbitmap_weight(sb, false); |
| 316 | } |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 317 | |
Ming Lei | cbb9950 | 2021-01-22 10:33:09 +0800 | [diff] [blame] | 318 | unsigned int sbitmap_weight(const struct sbitmap *sb) |
| 319 | { |
| 320 | return __sbitmap_weight(sb, true) - sbitmap_cleared(sb); |
| 321 | } |
| 322 | EXPORT_SYMBOL_GPL(sbitmap_weight); |
| 323 | |
Omar Sandoval | 24af1ccf | 2017-01-25 14:32:13 -0800 | [diff] [blame] | 324 | void sbitmap_show(struct sbitmap *sb, struct seq_file *m) |
| 325 | { |
| 326 | seq_printf(m, "depth=%u\n", sb->depth); |
Ming Lei | cbb9950 | 2021-01-22 10:33:09 +0800 | [diff] [blame] | 327 | seq_printf(m, "busy=%u\n", sbitmap_weight(sb)); |
Jens Axboe | ea86ea2 | 2018-11-30 13:18:06 -0700 | [diff] [blame] | 328 | seq_printf(m, "cleared=%u\n", sbitmap_cleared(sb)); |
Omar Sandoval | 24af1ccf | 2017-01-25 14:32:13 -0800 | [diff] [blame] | 329 | seq_printf(m, "bits_per_word=%u\n", 1U << sb->shift); |
| 330 | seq_printf(m, "map_nr=%u\n", sb->map_nr); |
| 331 | } |
| 332 | EXPORT_SYMBOL_GPL(sbitmap_show); |
| 333 | |
| 334 | static inline void emit_byte(struct seq_file *m, unsigned int offset, u8 byte) |
| 335 | { |
| 336 | if ((offset & 0xf) == 0) { |
| 337 | if (offset != 0) |
| 338 | seq_putc(m, '\n'); |
| 339 | seq_printf(m, "%08x:", offset); |
| 340 | } |
| 341 | if ((offset & 0x1) == 0) |
| 342 | seq_putc(m, ' '); |
| 343 | seq_printf(m, "%02x", byte); |
| 344 | } |
| 345 | |
| 346 | void sbitmap_bitmap_show(struct sbitmap *sb, struct seq_file *m) |
| 347 | { |
| 348 | u8 byte = 0; |
| 349 | unsigned int byte_bits = 0; |
| 350 | unsigned int offset = 0; |
| 351 | int i; |
| 352 | |
| 353 | for (i = 0; i < sb->map_nr; i++) { |
| 354 | unsigned long word = READ_ONCE(sb->map[i].word); |
John Garry | 6bf0eb5 | 2020-07-01 16:06:25 +0800 | [diff] [blame] | 355 | unsigned long cleared = READ_ONCE(sb->map[i].cleared); |
Ming Lei | 3301bc5 | 2022-01-10 15:29:45 +0800 | [diff] [blame] | 356 | unsigned int word_bits = __map_depth(sb, i); |
Omar Sandoval | 24af1ccf | 2017-01-25 14:32:13 -0800 | [diff] [blame] | 357 | |
John Garry | 6bf0eb5 | 2020-07-01 16:06:25 +0800 | [diff] [blame] | 358 | word &= ~cleared; |
| 359 | |
Omar Sandoval | 24af1ccf | 2017-01-25 14:32:13 -0800 | [diff] [blame] | 360 | while (word_bits > 0) { |
| 361 | unsigned int bits = min(8 - byte_bits, word_bits); |
| 362 | |
| 363 | byte |= (word & (BIT(bits) - 1)) << byte_bits; |
| 364 | byte_bits += bits; |
| 365 | if (byte_bits == 8) { |
| 366 | emit_byte(m, offset, byte); |
| 367 | byte = 0; |
| 368 | byte_bits = 0; |
| 369 | offset++; |
| 370 | } |
| 371 | word >>= bits; |
| 372 | word_bits -= bits; |
| 373 | } |
| 374 | } |
| 375 | if (byte_bits) { |
| 376 | emit_byte(m, offset, byte); |
| 377 | offset++; |
| 378 | } |
| 379 | if (offset) |
| 380 | seq_putc(m, '\n'); |
| 381 | } |
| 382 | EXPORT_SYMBOL_GPL(sbitmap_bitmap_show); |
| 383 | |
Omar Sandoval | a327553 | 2018-05-09 17:16:31 -0700 | [diff] [blame] | 384 | static unsigned int sbq_calc_wake_batch(struct sbitmap_queue *sbq, |
| 385 | unsigned int depth) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 386 | { |
| 387 | unsigned int wake_batch; |
Omar Sandoval | a327553 | 2018-05-09 17:16:31 -0700 | [diff] [blame] | 388 | unsigned int shallow_depth; |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 389 | |
| 390 | /* |
| 391 | * For each batch, we wake up one queue. We need to make sure that our |
Omar Sandoval | a327553 | 2018-05-09 17:16:31 -0700 | [diff] [blame] | 392 | * batch size is small enough that the full depth of the bitmap, |
| 393 | * potentially limited by a shallow depth, is enough to wake up all of |
| 394 | * the queues. |
| 395 | * |
| 396 | * Each full word of the bitmap has bits_per_word bits, and there might |
| 397 | * be a partial word. There are depth / bits_per_word full words and |
| 398 | * depth % bits_per_word bits left over. In bitwise arithmetic: |
| 399 | * |
| 400 | * bits_per_word = 1 << shift |
| 401 | * depth / bits_per_word = depth >> shift |
| 402 | * depth % bits_per_word = depth & ((1 << shift) - 1) |
| 403 | * |
| 404 | * Each word can be limited to sbq->min_shallow_depth bits. |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 405 | */ |
Omar Sandoval | a327553 | 2018-05-09 17:16:31 -0700 | [diff] [blame] | 406 | shallow_depth = min(1U << sbq->sb.shift, sbq->min_shallow_depth); |
| 407 | depth = ((depth >> sbq->sb.shift) * shallow_depth + |
| 408 | min(depth & ((1U << sbq->sb.shift) - 1), shallow_depth)); |
| 409 | wake_batch = clamp_t(unsigned int, depth / SBQ_WAIT_QUEUES, 1, |
| 410 | SBQ_WAKE_BATCH); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 411 | |
| 412 | return wake_batch; |
| 413 | } |
| 414 | |
| 415 | int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, |
Omar Sandoval | f4a644d | 2016-09-17 01:28:24 -0700 | [diff] [blame] | 416 | int shift, bool round_robin, gfp_t flags, int node) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 417 | { |
| 418 | int ret; |
| 419 | int i; |
| 420 | |
Ming Lei | efe1f3a | 2021-01-22 10:33:06 +0800 | [diff] [blame] | 421 | ret = sbitmap_init_node(&sbq->sb, depth, shift, flags, node, |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 422 | round_robin, true); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 423 | if (ret) |
| 424 | return ret; |
| 425 | |
Omar Sandoval | a327553 | 2018-05-09 17:16:31 -0700 | [diff] [blame] | 426 | sbq->min_shallow_depth = UINT_MAX; |
| 427 | sbq->wake_batch = sbq_calc_wake_batch(sbq, depth); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 428 | atomic_set(&sbq->wake_index, 0); |
Jens Axboe | 5d2ee71 | 2018-11-29 17:36:41 -0700 | [diff] [blame] | 429 | atomic_set(&sbq->ws_active, 0); |
Gabriel Krisman Bertazi | 4f8126b | 2022-11-05 19:10:55 -0400 | [diff] [blame] | 430 | atomic_set(&sbq->completion_cnt, 0); |
| 431 | atomic_set(&sbq->wakeup_cnt, 0); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 432 | |
Omar Sandoval | 48e2816 | 2016-09-17 01:28:22 -0700 | [diff] [blame] | 433 | sbq->ws = kzalloc_node(SBQ_WAIT_QUEUES * sizeof(*sbq->ws), flags, node); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 434 | if (!sbq->ws) { |
| 435 | sbitmap_free(&sbq->sb); |
| 436 | return -ENOMEM; |
| 437 | } |
| 438 | |
Gabriel Krisman Bertazi | 4f8126b | 2022-11-05 19:10:55 -0400 | [diff] [blame] | 439 | for (i = 0; i < SBQ_WAIT_QUEUES; i++) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 440 | init_waitqueue_head(&sbq->ws[i].wait); |
Omar Sandoval | f4a644d | 2016-09-17 01:28:24 -0700 | [diff] [blame] | 441 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 442 | return 0; |
| 443 | } |
| 444 | EXPORT_SYMBOL_GPL(sbitmap_queue_init_node); |
| 445 | |
Laibin Qiu | 180dccb | 2022-01-13 10:55:36 +0800 | [diff] [blame] | 446 | static void sbitmap_queue_update_wake_batch(struct sbitmap_queue *sbq, |
| 447 | unsigned int depth) |
| 448 | { |
| 449 | unsigned int wake_batch; |
| 450 | |
| 451 | wake_batch = sbq_calc_wake_batch(sbq, depth); |
Gabriel Krisman Bertazi | 4f8126b | 2022-11-05 19:10:55 -0400 | [diff] [blame] | 452 | if (sbq->wake_batch != wake_batch) |
| 453 | WRITE_ONCE(sbq->wake_batch, wake_batch); |
Laibin Qiu | 180dccb | 2022-01-13 10:55:36 +0800 | [diff] [blame] | 454 | } |
| 455 | |
| 456 | void sbitmap_queue_recalculate_wake_batch(struct sbitmap_queue *sbq, |
| 457 | unsigned int users) |
| 458 | { |
| 459 | unsigned int wake_batch; |
Laibin Qiu | 10825410 | 2022-01-27 18:00:47 +0800 | [diff] [blame] | 460 | unsigned int depth = (sbq->sb.depth + users - 1) / users; |
Laibin Qiu | 180dccb | 2022-01-13 10:55:36 +0800 | [diff] [blame] | 461 | |
Laibin Qiu | 10825410 | 2022-01-27 18:00:47 +0800 | [diff] [blame] | 462 | wake_batch = clamp_val(depth / SBQ_WAIT_QUEUES, |
Kemeng Shi | b5fcf78 | 2023-01-17 04:50:59 +0800 | [diff] [blame] | 463 | 1, SBQ_WAKE_BATCH); |
Gabriel Krisman Bertazi | 4f8126b | 2022-11-05 19:10:55 -0400 | [diff] [blame] | 464 | |
| 465 | WRITE_ONCE(sbq->wake_batch, wake_batch); |
Laibin Qiu | 180dccb | 2022-01-13 10:55:36 +0800 | [diff] [blame] | 466 | } |
| 467 | EXPORT_SYMBOL_GPL(sbitmap_queue_recalculate_wake_batch); |
| 468 | |
Omar Sandoval | a327553 | 2018-05-09 17:16:31 -0700 | [diff] [blame] | 469 | void sbitmap_queue_resize(struct sbitmap_queue *sbq, unsigned int depth) |
| 470 | { |
| 471 | sbitmap_queue_update_wake_batch(sbq, depth); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 472 | sbitmap_resize(&sbq->sb, depth); |
| 473 | } |
| 474 | EXPORT_SYMBOL_GPL(sbitmap_queue_resize); |
| 475 | |
Omar Sandoval | f4a644d | 2016-09-17 01:28:24 -0700 | [diff] [blame] | 476 | int __sbitmap_queue_get(struct sbitmap_queue *sbq) |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame] | 477 | { |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 478 | return sbitmap_get(&sbq->sb); |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame] | 479 | } |
| 480 | EXPORT_SYMBOL_GPL(__sbitmap_queue_get); |
| 481 | |
Jens Axboe | 9672b0d | 2021-10-09 13:02:23 -0600 | [diff] [blame] | 482 | unsigned long __sbitmap_queue_get_batch(struct sbitmap_queue *sbq, int nr_tags, |
| 483 | unsigned int *offset) |
| 484 | { |
| 485 | struct sbitmap *sb = &sbq->sb; |
| 486 | unsigned int hint, depth; |
| 487 | unsigned long index, nr; |
| 488 | int i; |
| 489 | |
| 490 | if (unlikely(sb->round_robin)) |
| 491 | return 0; |
| 492 | |
| 493 | depth = READ_ONCE(sb->depth); |
| 494 | hint = update_alloc_hint_before_get(sb, depth); |
| 495 | |
| 496 | index = SB_NR_TO_INDEX(sb, hint); |
| 497 | |
| 498 | for (i = 0; i < sb->map_nr; i++) { |
| 499 | struct sbitmap_word *map = &sb->map[index]; |
| 500 | unsigned long get_mask; |
Ming Lei | 3301bc5 | 2022-01-10 15:29:45 +0800 | [diff] [blame] | 501 | unsigned int map_depth = __map_depth(sb, index); |
Jens Axboe | 9672b0d | 2021-10-09 13:02:23 -0600 | [diff] [blame] | 502 | |
| 503 | sbitmap_deferred_clear(map); |
Ming Lei | 3301bc5 | 2022-01-10 15:29:45 +0800 | [diff] [blame] | 504 | if (map->word == (1UL << (map_depth - 1)) - 1) |
wuchi | fbb564a | 2022-06-05 22:58:35 +0800 | [diff] [blame] | 505 | goto next; |
Jens Axboe | 9672b0d | 2021-10-09 13:02:23 -0600 | [diff] [blame] | 506 | |
Ming Lei | 3301bc5 | 2022-01-10 15:29:45 +0800 | [diff] [blame] | 507 | nr = find_first_zero_bit(&map->word, map_depth); |
| 508 | if (nr + nr_tags <= map_depth) { |
Jens Axboe | 9672b0d | 2021-10-09 13:02:23 -0600 | [diff] [blame] | 509 | atomic_long_t *ptr = (atomic_long_t *) &map->word; |
Uros Bizjak | c35227d | 2022-09-08 17:12:00 +0200 | [diff] [blame] | 510 | unsigned long val; |
Jens Axboe | 9672b0d | 2021-10-09 13:02:23 -0600 | [diff] [blame] | 511 | |
Liu Song | ddbfc34 | 2022-08-26 11:14:13 +0800 | [diff] [blame] | 512 | get_mask = ((1UL << nr_tags) - 1) << nr; |
Uros Bizjak | c35227d | 2022-09-08 17:12:00 +0200 | [diff] [blame] | 513 | val = READ_ONCE(map->word); |
Kemeng Shi | 903e86f | 2023-01-17 04:50:56 +0800 | [diff] [blame] | 514 | while (!atomic_long_try_cmpxchg(ptr, &val, |
| 515 | get_mask | val)) |
| 516 | ; |
Uros Bizjak | c35227d | 2022-09-08 17:12:00 +0200 | [diff] [blame] | 517 | get_mask = (get_mask & ~val) >> nr; |
Jens Axboe | 9672b0d | 2021-10-09 13:02:23 -0600 | [diff] [blame] | 518 | if (get_mask) { |
| 519 | *offset = nr + (index << sb->shift); |
| 520 | update_alloc_hint_after_get(sb, depth, hint, |
Liu Song | ddbfc34 | 2022-08-26 11:14:13 +0800 | [diff] [blame] | 521 | *offset + nr_tags - 1); |
Jens Axboe | 9672b0d | 2021-10-09 13:02:23 -0600 | [diff] [blame] | 522 | return get_mask; |
| 523 | } |
| 524 | } |
wuchi | fbb564a | 2022-06-05 22:58:35 +0800 | [diff] [blame] | 525 | next: |
Jens Axboe | 9672b0d | 2021-10-09 13:02:23 -0600 | [diff] [blame] | 526 | /* Jump to next index. */ |
| 527 | if (++index >= sb->map_nr) |
| 528 | index = 0; |
| 529 | } |
| 530 | |
| 531 | return 0; |
| 532 | } |
| 533 | |
John Garry | 3f60729 | 2022-02-08 20:07:04 +0800 | [diff] [blame] | 534 | int sbitmap_queue_get_shallow(struct sbitmap_queue *sbq, |
| 535 | unsigned int shallow_depth) |
Omar Sandoval | c05e667 | 2017-04-14 00:59:58 -0700 | [diff] [blame] | 536 | { |
Omar Sandoval | 61445b56 | 2018-05-09 17:29:24 -0700 | [diff] [blame] | 537 | WARN_ON_ONCE(shallow_depth < sbq->min_shallow_depth); |
| 538 | |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 539 | return sbitmap_get_shallow(&sbq->sb, shallow_depth); |
Omar Sandoval | c05e667 | 2017-04-14 00:59:58 -0700 | [diff] [blame] | 540 | } |
John Garry | 3f60729 | 2022-02-08 20:07:04 +0800 | [diff] [blame] | 541 | EXPORT_SYMBOL_GPL(sbitmap_queue_get_shallow); |
Omar Sandoval | c05e667 | 2017-04-14 00:59:58 -0700 | [diff] [blame] | 542 | |
Omar Sandoval | a327553 | 2018-05-09 17:16:31 -0700 | [diff] [blame] | 543 | void sbitmap_queue_min_shallow_depth(struct sbitmap_queue *sbq, |
| 544 | unsigned int min_shallow_depth) |
| 545 | { |
| 546 | sbq->min_shallow_depth = min_shallow_depth; |
| 547 | sbitmap_queue_update_wake_batch(sbq, sbq->sb.depth); |
| 548 | } |
| 549 | EXPORT_SYMBOL_GPL(sbitmap_queue_min_shallow_depth); |
| 550 | |
Gabriel Krisman Bertazi | 26edb30 | 2022-11-15 17:45:53 -0500 | [diff] [blame] | 551 | static void __sbitmap_queue_wake_up(struct sbitmap_queue *sbq, int nr) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 552 | { |
| 553 | int i, wake_index; |
| 554 | |
Jens Axboe | 5d2ee71 | 2018-11-29 17:36:41 -0700 | [diff] [blame] | 555 | if (!atomic_read(&sbq->ws_active)) |
Gabriel Krisman Bertazi | 26edb30 | 2022-11-15 17:45:53 -0500 | [diff] [blame] | 556 | return; |
Jens Axboe | 5d2ee71 | 2018-11-29 17:36:41 -0700 | [diff] [blame] | 557 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 558 | wake_index = atomic_read(&sbq->wake_index); |
| 559 | for (i = 0; i < SBQ_WAIT_QUEUES; i++) { |
| 560 | struct sbq_wait_state *ws = &sbq->ws[wake_index]; |
| 561 | |
Gabriel Krisman Bertazi | 976570b | 2022-11-15 17:45:51 -0500 | [diff] [blame] | 562 | /* |
| 563 | * Advance the index before checking the current queue. |
| 564 | * It improves fairness, by ensuring the queue doesn't |
| 565 | * need to be fully emptied before trying to wake up |
| 566 | * from the next one. |
| 567 | */ |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 568 | wake_index = sbq_index_inc(wake_index); |
Gabriel Krisman Bertazi | 976570b | 2022-11-15 17:45:51 -0500 | [diff] [blame] | 569 | |
Gabriel Krisman Bertazi | 26edb30 | 2022-11-15 17:45:53 -0500 | [diff] [blame] | 570 | /* |
| 571 | * It is sufficient to wake up at least one waiter to |
| 572 | * guarantee forward progress. |
| 573 | */ |
| 574 | if (waitqueue_active(&ws->wait) && |
| 575 | wake_up_nr(&ws->wait, nr)) |
| 576 | break; |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 577 | } |
| 578 | |
Gabriel Krisman Bertazi | 26edb30 | 2022-11-15 17:45:53 -0500 | [diff] [blame] | 579 | if (wake_index != atomic_read(&sbq->wake_index)) |
| 580 | atomic_set(&sbq->wake_index, wake_index); |
Jens Axboe | c854ab57 | 2018-05-14 12:17:31 -0600 | [diff] [blame] | 581 | } |
| 582 | |
Keith Busch | 4acb834 | 2022-09-09 11:40:22 -0700 | [diff] [blame] | 583 | void sbitmap_queue_wake_up(struct sbitmap_queue *sbq, int nr) |
Jens Axboe | c854ab57 | 2018-05-14 12:17:31 -0600 | [diff] [blame] | 584 | { |
Gabriel Krisman Bertazi | 4f8126b | 2022-11-05 19:10:55 -0400 | [diff] [blame] | 585 | unsigned int wake_batch = READ_ONCE(sbq->wake_batch); |
Gabriel Krisman Bertazi | 4f8126b | 2022-11-05 19:10:55 -0400 | [diff] [blame] | 586 | unsigned int wakeups; |
| 587 | |
| 588 | if (!atomic_read(&sbq->ws_active)) |
| 589 | return; |
| 590 | |
| 591 | atomic_add(nr, &sbq->completion_cnt); |
| 592 | wakeups = atomic_read(&sbq->wakeup_cnt); |
| 593 | |
| 594 | do { |
| 595 | if (atomic_read(&sbq->completion_cnt) - wakeups < wake_batch) |
| 596 | return; |
Gabriel Krisman Bertazi | 4f8126b | 2022-11-05 19:10:55 -0400 | [diff] [blame] | 597 | } while (!atomic_try_cmpxchg(&sbq->wakeup_cnt, |
| 598 | &wakeups, wakeups + wake_batch)); |
| 599 | |
Gabriel Krisman Bertazi | 26edb30 | 2022-11-15 17:45:53 -0500 | [diff] [blame] | 600 | __sbitmap_queue_wake_up(sbq, wake_batch); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 601 | } |
Jens Axboe | bce1b56 | 2022-09-04 06:39:25 -0600 | [diff] [blame] | 602 | EXPORT_SYMBOL_GPL(sbitmap_queue_wake_up); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 603 | |
Jens Axboe | 1aec5e4 | 2021-10-08 05:44:23 -0600 | [diff] [blame] | 604 | static inline void sbitmap_update_cpu_hint(struct sbitmap *sb, int cpu, int tag) |
| 605 | { |
| 606 | if (likely(!sb->round_robin && tag < sb->depth)) |
Jens Axboe | 9f8b93a | 2021-10-25 10:45:01 -0600 | [diff] [blame] | 607 | data_race(*per_cpu_ptr(sb->alloc_hint, cpu) = tag); |
Jens Axboe | 1aec5e4 | 2021-10-08 05:44:23 -0600 | [diff] [blame] | 608 | } |
| 609 | |
| 610 | void sbitmap_queue_clear_batch(struct sbitmap_queue *sbq, int offset, |
| 611 | int *tags, int nr_tags) |
| 612 | { |
| 613 | struct sbitmap *sb = &sbq->sb; |
| 614 | unsigned long *addr = NULL; |
| 615 | unsigned long mask = 0; |
| 616 | int i; |
| 617 | |
| 618 | smp_mb__before_atomic(); |
| 619 | for (i = 0; i < nr_tags; i++) { |
| 620 | const int tag = tags[i] - offset; |
| 621 | unsigned long *this_addr; |
| 622 | |
| 623 | /* since we're clearing a batch, skip the deferred map */ |
| 624 | this_addr = &sb->map[SB_NR_TO_INDEX(sb, tag)].word; |
| 625 | if (!addr) { |
| 626 | addr = this_addr; |
| 627 | } else if (addr != this_addr) { |
| 628 | atomic_long_andnot(mask, (atomic_long_t *) addr); |
| 629 | mask = 0; |
| 630 | addr = this_addr; |
| 631 | } |
| 632 | mask |= (1UL << SB_NR_TO_BIT(sb, tag)); |
| 633 | } |
| 634 | |
| 635 | if (mask) |
| 636 | atomic_long_andnot(mask, (atomic_long_t *) addr); |
| 637 | |
| 638 | smp_mb__after_atomic(); |
Keith Busch | 4acb834 | 2022-09-09 11:40:22 -0700 | [diff] [blame] | 639 | sbitmap_queue_wake_up(sbq, nr_tags); |
Jens Axboe | 1aec5e4 | 2021-10-08 05:44:23 -0600 | [diff] [blame] | 640 | sbitmap_update_cpu_hint(&sbq->sb, raw_smp_processor_id(), |
| 641 | tags[nr_tags - 1] - offset); |
| 642 | } |
| 643 | |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame] | 644 | void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr, |
Omar Sandoval | f4a644d | 2016-09-17 01:28:24 -0700 | [diff] [blame] | 645 | unsigned int cpu) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 646 | { |
Ming Lei | e6d1fa5 | 2019-03-22 09:13:51 +0800 | [diff] [blame] | 647 | /* |
| 648 | * Once the clear bit is set, the bit may be allocated out. |
| 649 | * |
Zhen Lei | 9dbbc3b | 2021-07-07 18:07:31 -0700 | [diff] [blame] | 650 | * Orders READ/WRITE on the associated instance(such as request |
Ming Lei | e6d1fa5 | 2019-03-22 09:13:51 +0800 | [diff] [blame] | 651 | * of blk_mq) by this bit for avoiding race with re-allocation, |
| 652 | * and its pair is the memory barrier implied in __sbitmap_get_word. |
| 653 | * |
| 654 | * One invariant is that the clear bit has to be zero when the bit |
| 655 | * is in use. |
| 656 | */ |
| 657 | smp_mb__before_atomic(); |
Jens Axboe | ea86ea2 | 2018-11-30 13:18:06 -0700 | [diff] [blame] | 658 | sbitmap_deferred_clear_bit(&sbq->sb, nr); |
| 659 | |
Ming Lei | e6fc464 | 2018-05-24 11:00:39 -0600 | [diff] [blame] | 660 | /* |
| 661 | * Pairs with the memory barrier in set_current_state() to ensure the |
| 662 | * proper ordering of clear_bit_unlock()/waitqueue_active() in the waker |
| 663 | * and test_and_set_bit_lock()/prepare_to_wait()/finish_wait() in the |
| 664 | * waiter. See the comment on waitqueue_active(). |
| 665 | */ |
| 666 | smp_mb__after_atomic(); |
Keith Busch | 4acb834 | 2022-09-09 11:40:22 -0700 | [diff] [blame] | 667 | sbitmap_queue_wake_up(sbq, 1); |
Jens Axboe | 1aec5e4 | 2021-10-08 05:44:23 -0600 | [diff] [blame] | 668 | sbitmap_update_cpu_hint(&sbq->sb, cpu, nr); |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 669 | } |
| 670 | EXPORT_SYMBOL_GPL(sbitmap_queue_clear); |
| 671 | |
| 672 | void sbitmap_queue_wake_all(struct sbitmap_queue *sbq) |
| 673 | { |
| 674 | int i, wake_index; |
| 675 | |
| 676 | /* |
Omar Sandoval | f66227d | 2017-01-18 11:55:21 -0800 | [diff] [blame] | 677 | * Pairs with the memory barrier in set_current_state() like in |
Ming Lei | e6fc464 | 2018-05-24 11:00:39 -0600 | [diff] [blame] | 678 | * sbitmap_queue_wake_up(). |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 679 | */ |
| 680 | smp_mb(); |
| 681 | wake_index = atomic_read(&sbq->wake_index); |
| 682 | for (i = 0; i < SBQ_WAIT_QUEUES; i++) { |
| 683 | struct sbq_wait_state *ws = &sbq->ws[wake_index]; |
| 684 | |
| 685 | if (waitqueue_active(&ws->wait)) |
| 686 | wake_up(&ws->wait); |
| 687 | |
| 688 | wake_index = sbq_index_inc(wake_index); |
| 689 | } |
| 690 | } |
| 691 | EXPORT_SYMBOL_GPL(sbitmap_queue_wake_all); |
Omar Sandoval | 24af1ccf | 2017-01-25 14:32:13 -0800 | [diff] [blame] | 692 | |
| 693 | void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m) |
| 694 | { |
| 695 | bool first; |
| 696 | int i; |
| 697 | |
| 698 | sbitmap_show(&sbq->sb, m); |
| 699 | |
| 700 | seq_puts(m, "alloc_hint={"); |
| 701 | first = true; |
| 702 | for_each_possible_cpu(i) { |
| 703 | if (!first) |
| 704 | seq_puts(m, ", "); |
| 705 | first = false; |
Ming Lei | c548e62 | 2021-01-22 10:33:08 +0800 | [diff] [blame] | 706 | seq_printf(m, "%u", *per_cpu_ptr(sbq->sb.alloc_hint, i)); |
Omar Sandoval | 24af1ccf | 2017-01-25 14:32:13 -0800 | [diff] [blame] | 707 | } |
| 708 | seq_puts(m, "}\n"); |
| 709 | |
| 710 | seq_printf(m, "wake_batch=%u\n", sbq->wake_batch); |
| 711 | seq_printf(m, "wake_index=%d\n", atomic_read(&sbq->wake_index)); |
Jens Axboe | 5d2ee71 | 2018-11-29 17:36:41 -0700 | [diff] [blame] | 712 | seq_printf(m, "ws_active=%d\n", atomic_read(&sbq->ws_active)); |
Omar Sandoval | 24af1ccf | 2017-01-25 14:32:13 -0800 | [diff] [blame] | 713 | |
| 714 | seq_puts(m, "ws={\n"); |
| 715 | for (i = 0; i < SBQ_WAIT_QUEUES; i++) { |
| 716 | struct sbq_wait_state *ws = &sbq->ws[i]; |
Gabriel Krisman Bertazi | 4f8126b | 2022-11-05 19:10:55 -0400 | [diff] [blame] | 717 | seq_printf(m, "\t{.wait=%s},\n", |
Omar Sandoval | 24af1ccf | 2017-01-25 14:32:13 -0800 | [diff] [blame] | 718 | waitqueue_active(&ws->wait) ? "active" : "inactive"); |
| 719 | } |
| 720 | seq_puts(m, "}\n"); |
| 721 | |
Ming Lei | efe1f3a | 2021-01-22 10:33:06 +0800 | [diff] [blame] | 722 | seq_printf(m, "round_robin=%d\n", sbq->sb.round_robin); |
Omar Sandoval | a327553 | 2018-05-09 17:16:31 -0700 | [diff] [blame] | 723 | seq_printf(m, "min_shallow_depth=%u\n", sbq->min_shallow_depth); |
Omar Sandoval | 24af1ccf | 2017-01-25 14:32:13 -0800 | [diff] [blame] | 724 | } |
| 725 | EXPORT_SYMBOL_GPL(sbitmap_queue_show); |
Jens Axboe | 5d2ee71 | 2018-11-29 17:36:41 -0700 | [diff] [blame] | 726 | |
Jens Axboe | 9f6b7ef | 2018-12-20 08:49:00 -0700 | [diff] [blame] | 727 | void sbitmap_add_wait_queue(struct sbitmap_queue *sbq, |
| 728 | struct sbq_wait_state *ws, |
| 729 | struct sbq_wait *sbq_wait) |
| 730 | { |
| 731 | if (!sbq_wait->sbq) { |
| 732 | sbq_wait->sbq = sbq; |
| 733 | atomic_inc(&sbq->ws_active); |
David Jeffery | df034c9 | 2019-12-17 11:00:24 -0500 | [diff] [blame] | 734 | add_wait_queue(&ws->wait, &sbq_wait->wait); |
Jens Axboe | 9f6b7ef | 2018-12-20 08:49:00 -0700 | [diff] [blame] | 735 | } |
Jens Axboe | 9f6b7ef | 2018-12-20 08:49:00 -0700 | [diff] [blame] | 736 | } |
| 737 | EXPORT_SYMBOL_GPL(sbitmap_add_wait_queue); |
| 738 | |
| 739 | void sbitmap_del_wait_queue(struct sbq_wait *sbq_wait) |
| 740 | { |
| 741 | list_del_init(&sbq_wait->wait.entry); |
| 742 | if (sbq_wait->sbq) { |
| 743 | atomic_dec(&sbq_wait->sbq->ws_active); |
| 744 | sbq_wait->sbq = NULL; |
| 745 | } |
| 746 | } |
| 747 | EXPORT_SYMBOL_GPL(sbitmap_del_wait_queue); |
| 748 | |
Jens Axboe | 5d2ee71 | 2018-11-29 17:36:41 -0700 | [diff] [blame] | 749 | void sbitmap_prepare_to_wait(struct sbitmap_queue *sbq, |
| 750 | struct sbq_wait_state *ws, |
| 751 | struct sbq_wait *sbq_wait, int state) |
| 752 | { |
Jens Axboe | 9f6b7ef | 2018-12-20 08:49:00 -0700 | [diff] [blame] | 753 | if (!sbq_wait->sbq) { |
Jens Axboe | 5d2ee71 | 2018-11-29 17:36:41 -0700 | [diff] [blame] | 754 | atomic_inc(&sbq->ws_active); |
Jens Axboe | 9f6b7ef | 2018-12-20 08:49:00 -0700 | [diff] [blame] | 755 | sbq_wait->sbq = sbq; |
Jens Axboe | 5d2ee71 | 2018-11-29 17:36:41 -0700 | [diff] [blame] | 756 | } |
| 757 | prepare_to_wait_exclusive(&ws->wait, &sbq_wait->wait, state); |
| 758 | } |
| 759 | EXPORT_SYMBOL_GPL(sbitmap_prepare_to_wait); |
| 760 | |
| 761 | void sbitmap_finish_wait(struct sbitmap_queue *sbq, struct sbq_wait_state *ws, |
| 762 | struct sbq_wait *sbq_wait) |
| 763 | { |
| 764 | finish_wait(&ws->wait, &sbq_wait->wait); |
Jens Axboe | 9f6b7ef | 2018-12-20 08:49:00 -0700 | [diff] [blame] | 765 | if (sbq_wait->sbq) { |
Jens Axboe | 5d2ee71 | 2018-11-29 17:36:41 -0700 | [diff] [blame] | 766 | atomic_dec(&sbq->ws_active); |
Jens Axboe | 9f6b7ef | 2018-12-20 08:49:00 -0700 | [diff] [blame] | 767 | sbq_wait->sbq = NULL; |
Jens Axboe | 5d2ee71 | 2018-11-29 17:36:41 -0700 | [diff] [blame] | 768 | } |
| 769 | } |
| 770 | EXPORT_SYMBOL_GPL(sbitmap_finish_wait); |