diff options
| -rw-r--r-- | block/blk-mq-tag.c | 11 | ||||
| -rw-r--r-- | drivers/target/iscsi/iscsi_target_util.c | 12 | ||||
| -rw-r--r-- | include/linux/sbitmap.h | 34 | ||||
| -rw-r--r-- | lib/sbitmap.c | 28 |
4 files changed, 74 insertions, 11 deletions
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c index 87bc5df72d48..2089c6c62f44 100644 --- a/block/blk-mq-tag.c +++ b/block/blk-mq-tag.c @@ -110,7 +110,7 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) struct blk_mq_tags *tags = blk_mq_tags_from_data(data); struct sbitmap_queue *bt; struct sbq_wait_state *ws; - DEFINE_WAIT(wait); + DEFINE_SBQ_WAIT(wait); unsigned int tag_offset; bool drop_ctx; int tag; @@ -154,8 +154,7 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) if (tag != -1) break; - prepare_to_wait_exclusive(&ws->wait, &wait, - TASK_UNINTERRUPTIBLE); + sbitmap_prepare_to_wait(bt, ws, &wait, TASK_UNINTERRUPTIBLE); tag = __blk_mq_get_tag(data, bt); if (tag != -1) @@ -167,6 +166,8 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) bt_prev = bt; io_schedule(); + sbitmap_finish_wait(bt, ws, &wait); + data->ctx = blk_mq_get_ctx(data->q); data->hctx = blk_mq_map_queue(data->q, data->cmd_flags, data->ctx->cpu); @@ -176,8 +177,6 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) else bt = &tags->bitmap_tags; - finish_wait(&ws->wait, &wait); - /* * If destination hw queue is changed, fake wake up on * previous queue for compensating the wake up miss, so @@ -192,7 +191,7 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data) if (drop_ctx && data->ctx) blk_mq_put_ctx(data->ctx); - finish_wait(&ws->wait, &wait); + sbitmap_finish_wait(bt, ws, &wait); found_tag: return tag + tag_offset; diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c index 36b742932c72..86987da86dd6 100644 --- a/drivers/target/iscsi/iscsi_target_util.c +++ b/drivers/target/iscsi/iscsi_target_util.c @@ -150,24 +150,26 @@ void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd) static int iscsit_wait_for_tag(struct se_session *se_sess, int state, int *cpup) { int tag = -1; - DEFINE_WAIT(wait); + DEFINE_SBQ_WAIT(wait); struct sbq_wait_state *ws; + struct sbitmap_queue *sbq; if (state == TASK_RUNNING) return tag; - ws = &se_sess->sess_tag_pool.ws[0]; + sbq = &se_sess->sess_tag_pool; + ws = &sbq->ws[0]; for (;;) { - prepare_to_wait_exclusive(&ws->wait, &wait, state); + sbitmap_prepare_to_wait(sbq, ws, &wait, state); if (signal_pending_state(state, current)) break; - tag = sbitmap_queue_get(&se_sess->sess_tag_pool, cpup); + tag = sbitmap_queue_get(sbq, cpup); if (tag >= 0) break; schedule(); } - finish_wait(&ws->wait, &wait); + sbitmap_finish_wait(sbq, ws, &wait); return tag; } diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h index 81359d45751e..92806a2dbab7 100644 --- a/include/linux/sbitmap.h +++ b/include/linux/sbitmap.h @@ -135,6 +135,11 @@ struct sbitmap_queue { */ struct sbq_wait_state *ws; + /* + * @ws_active: count of currently active ws waitqueues + */ + atomic_t ws_active; + /** * @round_robin: Allocate bits in strict round-robin order. */ @@ -552,4 +557,33 @@ void sbitmap_queue_wake_up(struct sbitmap_queue *sbq); */ void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m); +struct sbq_wait { + int accounted; + struct wait_queue_entry wait; +}; + +#define DEFINE_SBQ_WAIT(name) \ + struct sbq_wait name = { \ + .accounted = 0, \ + .wait = { \ + .private = current, \ + .func = autoremove_wake_function, \ + .entry = LIST_HEAD_INIT((name).wait.entry), \ + } \ + } + +/* + * Wrapper around prepare_to_wait_exclusive(), which maintains some extra + * internal state. + */ +void sbitmap_prepare_to_wait(struct sbitmap_queue *sbq, + struct sbq_wait_state *ws, + struct sbq_wait *sbq_wait, int state); + +/* + * Must be paired with sbitmap_prepare_to_wait(). + */ +void sbitmap_finish_wait(struct sbitmap_queue *sbq, struct sbq_wait_state *ws, + struct sbq_wait *sbq_wait); + #endif /* __LINUX_SCALE_BITMAP_H */ diff --git a/lib/sbitmap.c b/lib/sbitmap.c index f99382e59314..a89fbe7cf6ca 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -394,6 +394,7 @@ int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth, sbq->min_shallow_depth = UINT_MAX; sbq->wake_batch = sbq_calc_wake_batch(sbq, depth); atomic_set(&sbq->wake_index, 0); + atomic_set(&sbq->ws_active, 0); sbq->ws = kzalloc_node(SBQ_WAIT_QUEUES * sizeof(*sbq->ws), flags, node); if (!sbq->ws) { @@ -509,6 +510,9 @@ static struct sbq_wait_state *sbq_wake_ptr(struct sbitmap_queue *sbq) { int i, wake_index; + if (!atomic_read(&sbq->ws_active)) + return NULL; + wake_index = atomic_read(&sbq->wake_index); for (i = 0; i < SBQ_WAIT_QUEUES; i++) { struct sbq_wait_state *ws = &sbq->ws[wake_index]; @@ -634,6 +638,7 @@ void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m) seq_printf(m, "wake_batch=%u\n", sbq->wake_batch); seq_printf(m, "wake_index=%d\n", atomic_read(&sbq->wake_index)); + seq_printf(m, "ws_active=%d\n", atomic_read(&sbq->ws_active)); seq_puts(m, "ws={\n"); for (i = 0; i < SBQ_WAIT_QUEUES; i++) { @@ -649,3 +654,26 @@ void sbitmap_queue_show(struct sbitmap_queue *sbq, struct seq_file *m) seq_printf(m, "min_shallow_depth=%u\n", sbq->min_shallow_depth); } EXPORT_SYMBOL_GPL(sbitmap_queue_show); + +void sbitmap_prepare_to_wait(struct sbitmap_queue *sbq, + struct sbq_wait_state *ws, + struct sbq_wait *sbq_wait, int state) +{ + if (!sbq_wait->accounted) { + atomic_inc(&sbq->ws_active); + sbq_wait->accounted = 1; + } + prepare_to_wait_exclusive(&ws->wait, &sbq_wait->wait, state); +} +EXPORT_SYMBOL_GPL(sbitmap_prepare_to_wait); + +void sbitmap_finish_wait(struct sbitmap_queue *sbq, struct sbq_wait_state *ws, + struct sbq_wait *sbq_wait) +{ + finish_wait(&ws->wait, &sbq_wait->wait); + if (sbq_wait->accounted) { + atomic_dec(&sbq->ws_active); + sbq_wait->accounted = 0; + } +} +EXPORT_SYMBOL_GPL(sbitmap_finish_wait); |