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-rw-r--r--block/blk-mq-sched.c58
-rw-r--r--block/blk-mq-sched.h9
-rw-r--r--block/blk-mq.c16
-rw-r--r--include/linux/blkdev.h2
4 files changed, 61 insertions, 24 deletions
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 1f5b692526ae..0ded5e846335 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -68,6 +68,45 @@ static void blk_mq_sched_assign_ioc(struct request_queue *q,
__blk_mq_sched_assign_ioc(q, rq, bio, ioc);
}
+/*
+ * Mark a hardware queue as needing a restart. For shared queues, maintain
+ * a count of how many hardware queues are marked for restart.
+ */
+static void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx)
+{
+ if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ return;
+
+ if (hctx->flags & BLK_MQ_F_TAG_SHARED) {
+ struct request_queue *q = hctx->queue;
+
+ if (!test_and_set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ atomic_inc(&q->shared_hctx_restart);
+ } else
+ set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
+}
+
+static bool blk_mq_sched_restart_hctx(struct blk_mq_hw_ctx *hctx)
+{
+ if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ return false;
+
+ if (hctx->flags & BLK_MQ_F_TAG_SHARED) {
+ struct request_queue *q = hctx->queue;
+
+ if (test_and_clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ atomic_dec(&q->shared_hctx_restart);
+ } else
+ clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
+
+ if (blk_mq_hctx_has_pending(hctx)) {
+ blk_mq_run_hw_queue(hctx, true);
+ return true;
+ }
+
+ return false;
+}
+
struct request *blk_mq_sched_get_request(struct request_queue *q,
struct bio *bio,
unsigned int op,
@@ -266,18 +305,6 @@ static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx,
return true;
}
-static bool blk_mq_sched_restart_hctx(struct blk_mq_hw_ctx *hctx)
-{
- if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) {
- clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
- if (blk_mq_hctx_has_pending(hctx)) {
- blk_mq_run_hw_queue(hctx, true);
- return true;
- }
- }
- return false;
-}
-
/**
* list_for_each_entry_rcu_rr - iterate in a round-robin fashion over rcu list
* @pos: loop cursor.
@@ -309,6 +336,13 @@ void blk_mq_sched_restart(struct blk_mq_hw_ctx *const hctx)
unsigned int i, j;
if (set->flags & BLK_MQ_F_TAG_SHARED) {
+ /*
+ * If this is 0, then we know that no hardware queues
+ * have RESTART marked. We're done.
+ */
+ if (!atomic_read(&queue->shared_hctx_restart))
+ return;
+
rcu_read_lock();
list_for_each_entry_rcu_rr(q, queue, &set->tag_list,
tag_set_list) {
diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h
index edafb5383b7b..5007edece51a 100644
--- a/block/blk-mq-sched.h
+++ b/block/blk-mq-sched.h
@@ -115,15 +115,6 @@ static inline bool blk_mq_sched_has_work(struct blk_mq_hw_ctx *hctx)
return false;
}
-/*
- * Mark a hardware queue as needing a restart.
- */
-static inline void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx)
-{
- if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
- set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
-}
-
static inline bool blk_mq_sched_needs_restart(struct blk_mq_hw_ctx *hctx)
{
return test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index bb66c96850b1..958cedaff8b8 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2103,20 +2103,30 @@ static void blk_mq_map_swqueue(struct request_queue *q,
}
}
+/*
+ * Caller needs to ensure that we're either frozen/quiesced, or that
+ * the queue isn't live yet.
+ */
static void queue_set_hctx_shared(struct request_queue *q, bool shared)
{
struct blk_mq_hw_ctx *hctx;
int i;
queue_for_each_hw_ctx(q, hctx, i) {
- if (shared)
+ if (shared) {
+ if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ atomic_inc(&q->shared_hctx_restart);
hctx->flags |= BLK_MQ_F_TAG_SHARED;
- else
+ } else {
+ if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
+ atomic_dec(&q->shared_hctx_restart);
hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
+ }
}
}
-static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared)
+static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set,
+ bool shared)
{
struct request_queue *q;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index b74a3edcb3da..1ddd36bd2173 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -391,6 +391,8 @@ struct request_queue {
int nr_rqs[2]; /* # allocated [a]sync rqs */
int nr_rqs_elvpriv; /* # allocated rqs w/ elvpriv */
+ atomic_t shared_hctx_restart;
+
struct blk_queue_stats *stats;
struct rq_wb *rq_wb;