Jens Axboe | 75bb462 | 2014-05-28 10:15:41 -0600 | [diff] [blame] | 1 | /* |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 2 | * Tag allocation using scalable bitmaps. Uses active queue tracking to support |
| 3 | * fairer distribution of tags between multiple submitters when a shared tag map |
| 4 | * is used. |
Jens Axboe | 75bb462 | 2014-05-28 10:15:41 -0600 | [diff] [blame] | 5 | * |
| 6 | * Copyright (C) 2013-2014 Jens Axboe |
| 7 | */ |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 8 | #include <linux/kernel.h> |
| 9 | #include <linux/module.h> |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 10 | #include <linux/random.h> |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 11 | |
| 12 | #include <linux/blk-mq.h> |
| 13 | #include "blk.h" |
| 14 | #include "blk-mq.h" |
| 15 | #include "blk-mq-tag.h" |
| 16 | |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 17 | bool blk_mq_has_free_tags(struct blk_mq_tags *tags) |
| 18 | { |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 19 | if (!tags) |
| 20 | return true; |
| 21 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 22 | return sbitmap_any_bit_clear(&tags->bitmap_tags.sb); |
Jens Axboe | 0d2602c | 2014-05-13 15:10:52 -0600 | [diff] [blame] | 23 | } |
| 24 | |
| 25 | /* |
| 26 | * If a previously inactive queue goes active, bump the active user count. |
| 27 | */ |
| 28 | bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx) |
| 29 | { |
| 30 | if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state) && |
| 31 | !test_and_set_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) |
| 32 | atomic_inc(&hctx->tags->active_queues); |
| 33 | |
| 34 | return true; |
| 35 | } |
| 36 | |
| 37 | /* |
Jens Axboe | aed3ea9 | 2014-12-22 14:04:42 -0700 | [diff] [blame] | 38 | * Wakeup all potentially sleeping on tags |
Jens Axboe | 0d2602c | 2014-05-13 15:10:52 -0600 | [diff] [blame] | 39 | */ |
Jens Axboe | aed3ea9 | 2014-12-22 14:04:42 -0700 | [diff] [blame] | 40 | void blk_mq_tag_wakeup_all(struct blk_mq_tags *tags, bool include_reserve) |
Jens Axboe | 0d2602c | 2014-05-13 15:10:52 -0600 | [diff] [blame] | 41 | { |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 42 | sbitmap_queue_wake_all(&tags->bitmap_tags); |
| 43 | if (include_reserve) |
| 44 | sbitmap_queue_wake_all(&tags->breserved_tags); |
Jens Axboe | 0d2602c | 2014-05-13 15:10:52 -0600 | [diff] [blame] | 45 | } |
| 46 | |
| 47 | /* |
Jens Axboe | e3a2b3f | 2014-05-20 11:49:02 -0600 | [diff] [blame] | 48 | * If a previously busy queue goes inactive, potential waiters could now |
| 49 | * be allowed to queue. Wake them up and check. |
| 50 | */ |
| 51 | void __blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx) |
| 52 | { |
| 53 | struct blk_mq_tags *tags = hctx->tags; |
| 54 | |
| 55 | if (!test_and_clear_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) |
| 56 | return; |
| 57 | |
| 58 | atomic_dec(&tags->active_queues); |
| 59 | |
Jens Axboe | aed3ea9 | 2014-12-22 14:04:42 -0700 | [diff] [blame] | 60 | blk_mq_tag_wakeup_all(tags, false); |
Jens Axboe | e3a2b3f | 2014-05-20 11:49:02 -0600 | [diff] [blame] | 61 | } |
| 62 | |
| 63 | /* |
Jens Axboe | 0d2602c | 2014-05-13 15:10:52 -0600 | [diff] [blame] | 64 | * For shared tag users, we track the number of currently active users |
| 65 | * and attempt to provide a fair share of the tag depth for each of them. |
| 66 | */ |
| 67 | static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 68 | struct sbitmap_queue *bt) |
Jens Axboe | 0d2602c | 2014-05-13 15:10:52 -0600 | [diff] [blame] | 69 | { |
| 70 | unsigned int depth, users; |
| 71 | |
| 72 | if (!hctx || !(hctx->flags & BLK_MQ_F_TAG_SHARED)) |
| 73 | return true; |
| 74 | if (!test_bit(BLK_MQ_S_TAG_ACTIVE, &hctx->state)) |
| 75 | return true; |
| 76 | |
| 77 | /* |
| 78 | * Don't try dividing an ant |
| 79 | */ |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 80 | if (bt->sb.depth == 1) |
Jens Axboe | 0d2602c | 2014-05-13 15:10:52 -0600 | [diff] [blame] | 81 | return true; |
| 82 | |
| 83 | users = atomic_read(&hctx->tags->active_queues); |
| 84 | if (!users) |
| 85 | return true; |
| 86 | |
| 87 | /* |
| 88 | * Allow at least some tags |
| 89 | */ |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 90 | depth = max((bt->sb.depth + users - 1) / users, 4U); |
Jens Axboe | 0d2602c | 2014-05-13 15:10:52 -0600 | [diff] [blame] | 91 | return atomic_read(&hctx->nr_active) < depth; |
| 92 | } |
| 93 | |
Shaohua Li | 24391c0 | 2015-01-23 14:18:00 -0700 | [diff] [blame] | 94 | #define BT_ALLOC_RR(tags) (tags->alloc_policy == BLK_TAG_ALLOC_RR) |
| 95 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 96 | static int __bt_get(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt, |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame^] | 97 | struct blk_mq_tags *tags) |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 98 | { |
Jens Axboe | 0d2602c | 2014-05-13 15:10:52 -0600 | [diff] [blame] | 99 | if (!hctx_may_queue(hctx, bt)) |
| 100 | return -1; |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame^] | 101 | return __sbitmap_queue_get(bt, BT_ALLOC_RR(tags)); |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 102 | } |
| 103 | |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame^] | 104 | static int bt_get(struct blk_mq_alloc_data *data, struct sbitmap_queue *bt, |
| 105 | struct blk_mq_hw_ctx *hctx, struct blk_mq_tags *tags) |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 106 | { |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 107 | struct sbq_wait_state *ws; |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 108 | DEFINE_WAIT(wait); |
| 109 | int tag; |
| 110 | |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame^] | 111 | tag = __bt_get(hctx, bt, tags); |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 112 | if (tag != -1) |
| 113 | return tag; |
| 114 | |
Christoph Hellwig | 6f3b0e8 | 2015-11-26 09:13:05 +0100 | [diff] [blame] | 115 | if (data->flags & BLK_MQ_REQ_NOWAIT) |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 116 | return -1; |
| 117 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 118 | ws = bt_wait_ptr(bt, hctx); |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 119 | do { |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 120 | prepare_to_wait(&ws->wait, &wait, TASK_UNINTERRUPTIBLE); |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 121 | |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame^] | 122 | tag = __bt_get(hctx, bt, tags); |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 123 | if (tag != -1) |
| 124 | break; |
| 125 | |
Bart Van Assche | b322320 | 2014-12-08 08:46:34 -0700 | [diff] [blame] | 126 | /* |
| 127 | * We're out of tags on this hardware queue, kick any |
| 128 | * pending IO submits before going to sleep waiting for |
Sam Bradshaw | bc188d8 | 2015-03-18 17:06:18 -0600 | [diff] [blame] | 129 | * some to complete. Note that hctx can be NULL here for |
| 130 | * reserved tag allocation. |
Bart Van Assche | b322320 | 2014-12-08 08:46:34 -0700 | [diff] [blame] | 131 | */ |
Sam Bradshaw | bc188d8 | 2015-03-18 17:06:18 -0600 | [diff] [blame] | 132 | if (hctx) |
| 133 | blk_mq_run_hw_queue(hctx, false); |
Bart Van Assche | b322320 | 2014-12-08 08:46:34 -0700 | [diff] [blame] | 134 | |
Jens Axboe | 080ff35 | 2014-12-08 08:49:06 -0700 | [diff] [blame] | 135 | /* |
| 136 | * Retry tag allocation after running the hardware queue, |
| 137 | * as running the queue may also have found completions. |
| 138 | */ |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame^] | 139 | tag = __bt_get(hctx, bt, tags); |
Jens Axboe | 080ff35 | 2014-12-08 08:49:06 -0700 | [diff] [blame] | 140 | if (tag != -1) |
| 141 | break; |
| 142 | |
Ming Lei | cb96a42 | 2014-06-01 00:43:37 +0800 | [diff] [blame] | 143 | blk_mq_put_ctx(data->ctx); |
| 144 | |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 145 | io_schedule(); |
Ming Lei | cb96a42 | 2014-06-01 00:43:37 +0800 | [diff] [blame] | 146 | |
| 147 | data->ctx = blk_mq_get_ctx(data->q); |
| 148 | data->hctx = data->q->mq_ops->map_queue(data->q, |
| 149 | data->ctx->cpu); |
Christoph Hellwig | 6f3b0e8 | 2015-11-26 09:13:05 +0100 | [diff] [blame] | 150 | if (data->flags & BLK_MQ_REQ_RESERVED) { |
Ming Lei | cb96a42 | 2014-06-01 00:43:37 +0800 | [diff] [blame] | 151 | bt = &data->hctx->tags->breserved_tags; |
| 152 | } else { |
Ming Lei | cb96a42 | 2014-06-01 00:43:37 +0800 | [diff] [blame] | 153 | hctx = data->hctx; |
| 154 | bt = &hctx->tags->bitmap_tags; |
| 155 | } |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 156 | finish_wait(&ws->wait, &wait); |
| 157 | ws = bt_wait_ptr(bt, hctx); |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 158 | } while (1); |
| 159 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 160 | finish_wait(&ws->wait, &wait); |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 161 | return tag; |
| 162 | } |
| 163 | |
Ming Lei | cb96a42 | 2014-06-01 00:43:37 +0800 | [diff] [blame] | 164 | static unsigned int __blk_mq_get_tag(struct blk_mq_alloc_data *data) |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 165 | { |
| 166 | int tag; |
| 167 | |
Ming Lei | cb96a42 | 2014-06-01 00:43:37 +0800 | [diff] [blame] | 168 | tag = bt_get(data, &data->hctx->tags->bitmap_tags, data->hctx, |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame^] | 169 | data->hctx->tags); |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 170 | if (tag >= 0) |
Ming Lei | cb96a42 | 2014-06-01 00:43:37 +0800 | [diff] [blame] | 171 | return tag + data->hctx->tags->nr_reserved_tags; |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 172 | |
| 173 | return BLK_MQ_TAG_FAIL; |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 174 | } |
| 175 | |
Ming Lei | cb96a42 | 2014-06-01 00:43:37 +0800 | [diff] [blame] | 176 | static unsigned int __blk_mq_get_reserved_tag(struct blk_mq_alloc_data *data) |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 177 | { |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame^] | 178 | int tag; |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 179 | |
Ming Lei | cb96a42 | 2014-06-01 00:43:37 +0800 | [diff] [blame] | 180 | if (unlikely(!data->hctx->tags->nr_reserved_tags)) { |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 181 | WARN_ON_ONCE(1); |
| 182 | return BLK_MQ_TAG_FAIL; |
| 183 | } |
| 184 | |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame^] | 185 | tag = bt_get(data, &data->hctx->tags->breserved_tags, NULL, |
| 186 | data->hctx->tags); |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 187 | if (tag < 0) |
| 188 | return BLK_MQ_TAG_FAIL; |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 189 | |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 190 | return tag; |
| 191 | } |
| 192 | |
Ming Lei | cb96a42 | 2014-06-01 00:43:37 +0800 | [diff] [blame] | 193 | unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 194 | { |
Christoph Hellwig | 6f3b0e8 | 2015-11-26 09:13:05 +0100 | [diff] [blame] | 195 | if (data->flags & BLK_MQ_REQ_RESERVED) |
| 196 | return __blk_mq_get_reserved_tag(data); |
| 197 | return __blk_mq_get_tag(data); |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 198 | } |
| 199 | |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame^] | 200 | void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, |
| 201 | unsigned int tag) |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 202 | { |
Jens Axboe | 0d2602c | 2014-05-13 15:10:52 -0600 | [diff] [blame] | 203 | struct blk_mq_tags *tags = hctx->tags; |
| 204 | |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 205 | if (tag >= tags->nr_reserved_tags) { |
| 206 | const int real_tag = tag - tags->nr_reserved_tags; |
| 207 | |
Jens Axboe | 70114c3 | 2014-11-24 15:52:30 -0700 | [diff] [blame] | 208 | BUG_ON(real_tag >= tags->nr_tags); |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame^] | 209 | sbitmap_queue_clear(&tags->bitmap_tags, real_tag, |
| 210 | BT_ALLOC_RR(tags), ctx->cpu); |
Jens Axboe | 70114c3 | 2014-11-24 15:52:30 -0700 | [diff] [blame] | 211 | } else { |
| 212 | BUG_ON(tag >= tags->nr_reserved_tags); |
Omar Sandoval | 40aabb6 | 2016-09-17 01:28:23 -0700 | [diff] [blame^] | 213 | sbitmap_queue_clear(&tags->breserved_tags, tag, |
| 214 | BT_ALLOC_RR(tags), ctx->cpu); |
Jens Axboe | 70114c3 | 2014-11-24 15:52:30 -0700 | [diff] [blame] | 215 | } |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 216 | } |
| 217 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 218 | struct bt_iter_data { |
| 219 | struct blk_mq_hw_ctx *hctx; |
| 220 | busy_iter_fn *fn; |
| 221 | void *data; |
| 222 | bool reserved; |
| 223 | }; |
| 224 | |
| 225 | static bool bt_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 226 | { |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 227 | struct bt_iter_data *iter_data = data; |
| 228 | struct blk_mq_hw_ctx *hctx = iter_data->hctx; |
| 229 | struct blk_mq_tags *tags = hctx->tags; |
| 230 | bool reserved = iter_data->reserved; |
Christoph Hellwig | 81481eb | 2014-09-13 16:40:11 -0700 | [diff] [blame] | 231 | struct request *rq; |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 232 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 233 | if (!reserved) |
| 234 | bitnr += tags->nr_reserved_tags; |
| 235 | rq = tags->rqs[bitnr]; |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 236 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 237 | if (rq->q == hctx->queue) |
| 238 | iter_data->fn(hctx, rq, iter_data->data, reserved); |
| 239 | return true; |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 240 | } |
| 241 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 242 | static void bt_for_each(struct blk_mq_hw_ctx *hctx, struct sbitmap_queue *bt, |
| 243 | busy_iter_fn *fn, void *data, bool reserved) |
Keith Busch | f26cdc8 | 2015-06-01 09:29:53 -0600 | [diff] [blame] | 244 | { |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 245 | struct bt_iter_data iter_data = { |
| 246 | .hctx = hctx, |
| 247 | .fn = fn, |
| 248 | .data = data, |
| 249 | .reserved = reserved, |
| 250 | }; |
| 251 | |
| 252 | sbitmap_for_each_set(&bt->sb, bt_iter, &iter_data); |
| 253 | } |
| 254 | |
| 255 | struct bt_tags_iter_data { |
| 256 | struct blk_mq_tags *tags; |
| 257 | busy_tag_iter_fn *fn; |
| 258 | void *data; |
| 259 | bool reserved; |
| 260 | }; |
| 261 | |
| 262 | static bool bt_tags_iter(struct sbitmap *bitmap, unsigned int bitnr, void *data) |
| 263 | { |
| 264 | struct bt_tags_iter_data *iter_data = data; |
| 265 | struct blk_mq_tags *tags = iter_data->tags; |
| 266 | bool reserved = iter_data->reserved; |
Keith Busch | f26cdc8 | 2015-06-01 09:29:53 -0600 | [diff] [blame] | 267 | struct request *rq; |
Keith Busch | f26cdc8 | 2015-06-01 09:29:53 -0600 | [diff] [blame] | 268 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 269 | if (!reserved) |
| 270 | bitnr += tags->nr_reserved_tags; |
| 271 | rq = tags->rqs[bitnr]; |
Keith Busch | f26cdc8 | 2015-06-01 09:29:53 -0600 | [diff] [blame] | 272 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 273 | iter_data->fn(rq, iter_data->data, reserved); |
| 274 | return true; |
| 275 | } |
Keith Busch | f26cdc8 | 2015-06-01 09:29:53 -0600 | [diff] [blame] | 276 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 277 | static void bt_tags_for_each(struct blk_mq_tags *tags, struct sbitmap_queue *bt, |
| 278 | busy_tag_iter_fn *fn, void *data, bool reserved) |
| 279 | { |
| 280 | struct bt_tags_iter_data iter_data = { |
| 281 | .tags = tags, |
| 282 | .fn = fn, |
| 283 | .data = data, |
| 284 | .reserved = reserved, |
| 285 | }; |
| 286 | |
| 287 | if (tags->rqs) |
| 288 | sbitmap_for_each_set(&bt->sb, bt_tags_iter, &iter_data); |
Keith Busch | f26cdc8 | 2015-06-01 09:29:53 -0600 | [diff] [blame] | 289 | } |
| 290 | |
Sagi Grimberg | e8f1e16 | 2016-03-10 13:58:49 +0200 | [diff] [blame] | 291 | static void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags, |
| 292 | busy_tag_iter_fn *fn, void *priv) |
Keith Busch | f26cdc8 | 2015-06-01 09:29:53 -0600 | [diff] [blame] | 293 | { |
| 294 | if (tags->nr_reserved_tags) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 295 | bt_tags_for_each(tags, &tags->breserved_tags, fn, priv, true); |
| 296 | bt_tags_for_each(tags, &tags->bitmap_tags, fn, priv, false); |
Keith Busch | f26cdc8 | 2015-06-01 09:29:53 -0600 | [diff] [blame] | 297 | } |
Keith Busch | f26cdc8 | 2015-06-01 09:29:53 -0600 | [diff] [blame] | 298 | |
Sagi Grimberg | e048948 | 2016-03-10 13:58:46 +0200 | [diff] [blame] | 299 | void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset, |
| 300 | busy_tag_iter_fn *fn, void *priv) |
| 301 | { |
| 302 | int i; |
| 303 | |
| 304 | for (i = 0; i < tagset->nr_hw_queues; i++) { |
| 305 | if (tagset->tags && tagset->tags[i]) |
| 306 | blk_mq_all_tag_busy_iter(tagset->tags[i], fn, priv); |
| 307 | } |
| 308 | } |
| 309 | EXPORT_SYMBOL(blk_mq_tagset_busy_iter); |
| 310 | |
Sagi Grimberg | 486cf98 | 2016-07-06 21:55:48 +0900 | [diff] [blame] | 311 | int blk_mq_reinit_tagset(struct blk_mq_tag_set *set) |
| 312 | { |
| 313 | int i, j, ret = 0; |
| 314 | |
| 315 | if (!set->ops->reinit_request) |
| 316 | goto out; |
| 317 | |
| 318 | for (i = 0; i < set->nr_hw_queues; i++) { |
| 319 | struct blk_mq_tags *tags = set->tags[i]; |
| 320 | |
| 321 | for (j = 0; j < tags->nr_tags; j++) { |
| 322 | if (!tags->rqs[j]) |
| 323 | continue; |
| 324 | |
| 325 | ret = set->ops->reinit_request(set->driver_data, |
| 326 | tags->rqs[j]); |
| 327 | if (ret) |
| 328 | goto out; |
| 329 | } |
| 330 | } |
| 331 | |
| 332 | out: |
| 333 | return ret; |
| 334 | } |
| 335 | EXPORT_SYMBOL_GPL(blk_mq_reinit_tagset); |
| 336 | |
Christoph Hellwig | 0bf6cd5 | 2015-09-27 21:01:51 +0200 | [diff] [blame] | 337 | void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn, |
Christoph Hellwig | 81481eb | 2014-09-13 16:40:11 -0700 | [diff] [blame] | 338 | void *priv) |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 339 | { |
Christoph Hellwig | 0bf6cd5 | 2015-09-27 21:01:51 +0200 | [diff] [blame] | 340 | struct blk_mq_hw_ctx *hctx; |
| 341 | int i; |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 342 | |
Christoph Hellwig | 0bf6cd5 | 2015-09-27 21:01:51 +0200 | [diff] [blame] | 343 | |
| 344 | queue_for_each_hw_ctx(q, hctx, i) { |
| 345 | struct blk_mq_tags *tags = hctx->tags; |
| 346 | |
| 347 | /* |
| 348 | * If not software queues are currently mapped to this |
| 349 | * hardware queue, there's nothing to check |
| 350 | */ |
| 351 | if (!blk_mq_hw_queue_mapped(hctx)) |
| 352 | continue; |
| 353 | |
| 354 | if (tags->nr_reserved_tags) |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 355 | bt_for_each(hctx, &tags->breserved_tags, fn, priv, true); |
| 356 | bt_for_each(hctx, &tags->bitmap_tags, fn, priv, false); |
Christoph Hellwig | 0bf6cd5 | 2015-09-27 21:01:51 +0200 | [diff] [blame] | 357 | } |
| 358 | |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 359 | } |
| 360 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 361 | static unsigned int bt_unused_tags(const struct sbitmap_queue *bt) |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 362 | { |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 363 | return bt->sb.depth - sbitmap_weight(&bt->sb); |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 364 | } |
| 365 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 366 | static int bt_alloc(struct sbitmap_queue *bt, unsigned int depth, int node) |
Jens Axboe | e3a2b3f | 2014-05-20 11:49:02 -0600 | [diff] [blame] | 367 | { |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 368 | return sbitmap_queue_init_node(bt, depth, -1, GFP_KERNEL, node); |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 369 | } |
| 370 | |
| 371 | static struct blk_mq_tags *blk_mq_init_bitmap_tags(struct blk_mq_tags *tags, |
Shaohua Li | 24391c0 | 2015-01-23 14:18:00 -0700 | [diff] [blame] | 372 | int node, int alloc_policy) |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 373 | { |
| 374 | unsigned int depth = tags->nr_tags - tags->nr_reserved_tags; |
| 375 | |
Shaohua Li | 24391c0 | 2015-01-23 14:18:00 -0700 | [diff] [blame] | 376 | tags->alloc_policy = alloc_policy; |
| 377 | |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 378 | if (bt_alloc(&tags->bitmap_tags, depth, node)) |
| 379 | goto free_tags; |
| 380 | if (bt_alloc(&tags->breserved_tags, tags->nr_reserved_tags, node)) |
| 381 | goto free_bitmap_tags; |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 382 | |
| 383 | return tags; |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 384 | free_bitmap_tags: |
| 385 | sbitmap_queue_free(&tags->bitmap_tags); |
| 386 | free_tags: |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 387 | kfree(tags); |
| 388 | return NULL; |
| 389 | } |
| 390 | |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 391 | struct blk_mq_tags *blk_mq_init_tags(unsigned int total_tags, |
Shaohua Li | 24391c0 | 2015-01-23 14:18:00 -0700 | [diff] [blame] | 392 | unsigned int reserved_tags, |
| 393 | int node, int alloc_policy) |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 394 | { |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 395 | struct blk_mq_tags *tags; |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 396 | |
| 397 | if (total_tags > BLK_MQ_TAG_MAX) { |
| 398 | pr_err("blk-mq: tag depth too large\n"); |
| 399 | return NULL; |
| 400 | } |
| 401 | |
| 402 | tags = kzalloc_node(sizeof(*tags), GFP_KERNEL, node); |
| 403 | if (!tags) |
| 404 | return NULL; |
| 405 | |
Keith Busch | f26cdc8 | 2015-06-01 09:29:53 -0600 | [diff] [blame] | 406 | if (!zalloc_cpumask_var(&tags->cpumask, GFP_KERNEL)) { |
| 407 | kfree(tags); |
| 408 | return NULL; |
| 409 | } |
| 410 | |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 411 | tags->nr_tags = total_tags; |
| 412 | tags->nr_reserved_tags = reserved_tags; |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 413 | |
Shaohua Li | 24391c0 | 2015-01-23 14:18:00 -0700 | [diff] [blame] | 414 | return blk_mq_init_bitmap_tags(tags, node, alloc_policy); |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 415 | } |
| 416 | |
| 417 | void blk_mq_free_tags(struct blk_mq_tags *tags) |
| 418 | { |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 419 | sbitmap_queue_free(&tags->bitmap_tags); |
| 420 | sbitmap_queue_free(&tags->breserved_tags); |
Junichi Nomura | f42d79a | 2015-10-14 05:02:15 +0000 | [diff] [blame] | 421 | free_cpumask_var(tags->cpumask); |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 422 | kfree(tags); |
| 423 | } |
| 424 | |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 425 | void blk_mq_tag_init_last_tag(struct blk_mq_tags *tags, unsigned int *tag) |
| 426 | { |
| 427 | unsigned int depth = tags->nr_tags - tags->nr_reserved_tags; |
| 428 | |
Ming Lei | 9d3d21a | 2014-05-10 15:43:14 -0600 | [diff] [blame] | 429 | *tag = prandom_u32() % depth; |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 430 | } |
| 431 | |
Jens Axboe | e3a2b3f | 2014-05-20 11:49:02 -0600 | [diff] [blame] | 432 | int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int tdepth) |
| 433 | { |
| 434 | tdepth -= tags->nr_reserved_tags; |
| 435 | if (tdepth > tags->nr_tags) |
| 436 | return -EINVAL; |
| 437 | |
| 438 | /* |
| 439 | * Don't need (or can't) update reserved tags here, they remain |
| 440 | * static and should never need resizing. |
| 441 | */ |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 442 | sbitmap_queue_resize(&tags->bitmap_tags, tdepth); |
| 443 | |
Jens Axboe | aed3ea9 | 2014-12-22 14:04:42 -0700 | [diff] [blame] | 444 | blk_mq_tag_wakeup_all(tags, false); |
Jens Axboe | e3a2b3f | 2014-05-20 11:49:02 -0600 | [diff] [blame] | 445 | return 0; |
| 446 | } |
| 447 | |
Bart Van Assche | 205fb5f | 2014-10-30 14:45:11 +0100 | [diff] [blame] | 448 | /** |
| 449 | * blk_mq_unique_tag() - return a tag that is unique queue-wide |
| 450 | * @rq: request for which to compute a unique tag |
| 451 | * |
| 452 | * The tag field in struct request is unique per hardware queue but not over |
| 453 | * all hardware queues. Hence this function that returns a tag with the |
| 454 | * hardware context index in the upper bits and the per hardware queue tag in |
| 455 | * the lower bits. |
| 456 | * |
| 457 | * Note: When called for a request that is queued on a non-multiqueue request |
| 458 | * queue, the hardware context index is set to zero. |
| 459 | */ |
| 460 | u32 blk_mq_unique_tag(struct request *rq) |
| 461 | { |
| 462 | struct request_queue *q = rq->q; |
| 463 | struct blk_mq_hw_ctx *hctx; |
| 464 | int hwq = 0; |
| 465 | |
| 466 | if (q->mq_ops) { |
| 467 | hctx = q->mq_ops->map_queue(q, rq->mq_ctx->cpu); |
| 468 | hwq = hctx->queue_num; |
| 469 | } |
| 470 | |
| 471 | return (hwq << BLK_MQ_UNIQUE_TAG_BITS) | |
| 472 | (rq->tag & BLK_MQ_UNIQUE_TAG_MASK); |
| 473 | } |
| 474 | EXPORT_SYMBOL(blk_mq_unique_tag); |
| 475 | |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 476 | ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page) |
| 477 | { |
| 478 | char *orig_page = page; |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 479 | unsigned int free, res; |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 480 | |
| 481 | if (!tags) |
| 482 | return 0; |
| 483 | |
Jens Axboe | 59d13bf | 2014-05-09 13:41:15 -0600 | [diff] [blame] | 484 | page += sprintf(page, "nr_tags=%u, reserved_tags=%u, " |
| 485 | "bits_per_word=%u\n", |
| 486 | tags->nr_tags, tags->nr_reserved_tags, |
Omar Sandoval | 8845964 | 2016-09-17 08:38:44 -0600 | [diff] [blame] | 487 | 1U << tags->bitmap_tags.sb.shift); |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 488 | |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 489 | free = bt_unused_tags(&tags->bitmap_tags); |
| 490 | res = bt_unused_tags(&tags->breserved_tags); |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 491 | |
Jens Axboe | 4bb659b | 2014-05-09 09:36:49 -0600 | [diff] [blame] | 492 | page += sprintf(page, "nr_free=%u, nr_reserved=%u\n", free, res); |
Jens Axboe | 0d2602c | 2014-05-13 15:10:52 -0600 | [diff] [blame] | 493 | page += sprintf(page, "active_queues=%u\n", atomic_read(&tags->active_queues)); |
Jens Axboe | 320ae51 | 2013-10-24 09:20:05 +0100 | [diff] [blame] | 494 | |
| 495 | return page - orig_page; |
| 496 | } |