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Diffstat (limited to 'block/blk-mq.c')
-rw-r--r--block/blk-mq.c186
1 files changed, 88 insertions, 98 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 9c475a89e3af..555ada922cf0 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -21,7 +21,6 @@
#include <linux/llist.h>
#include <linux/cpu.h>
#include <linux/cache.h>
-#include <linux/sched/sysctl.h>
#include <linux/sched/topology.h>
#include <linux/sched/signal.h>
#include <linux/delay.h>
@@ -322,7 +321,7 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
RB_CLEAR_NODE(&rq->rb_node);
rq->tag = BLK_MQ_NO_TAG;
rq->internal_tag = BLK_MQ_NO_TAG;
- rq->start_time_ns = ktime_get_ns();
+ rq->start_time_ns = blk_time_get_ns();
rq->part = NULL;
blk_crypto_rq_set_defaults(rq);
}
@@ -332,7 +331,7 @@ EXPORT_SYMBOL(blk_rq_init);
static inline void blk_mq_rq_time_init(struct request *rq, u64 alloc_time_ns)
{
if (blk_mq_need_time_stamp(rq))
- rq->start_time_ns = ktime_get_ns();
+ rq->start_time_ns = blk_time_get_ns();
else
rq->start_time_ns = 0;
@@ -443,7 +442,7 @@ static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data)
/* alloc_time includes depth and tag waits */
if (blk_queue_rq_alloc_time(q))
- alloc_time_ns = ktime_get_ns();
+ alloc_time_ns = blk_time_get_ns();
if (data->cmd_flags & REQ_NOWAIT)
data->flags |= BLK_MQ_REQ_NOWAIT;
@@ -628,7 +627,7 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
/* alloc_time includes depth and tag waits */
if (blk_queue_rq_alloc_time(q))
- alloc_time_ns = ktime_get_ns();
+ alloc_time_ns = blk_time_get_ns();
/*
* If the tag allocator sleeps we could get an allocation for a
@@ -1041,7 +1040,7 @@ static inline void __blk_mq_end_request_acct(struct request *rq, u64 now)
inline void __blk_mq_end_request(struct request *rq, blk_status_t error)
{
if (blk_mq_need_time_stamp(rq))
- __blk_mq_end_request_acct(rq, ktime_get_ns());
+ __blk_mq_end_request_acct(rq, blk_time_get_ns());
blk_mq_finish_request(rq);
@@ -1084,7 +1083,7 @@ void blk_mq_end_request_batch(struct io_comp_batch *iob)
u64 now = 0;
if (iob->need_ts)
- now = ktime_get_ns();
+ now = blk_time_get_ns();
while ((rq = rq_list_pop(&iob->req_list)) != NULL) {
prefetch(rq->bio);
@@ -1167,10 +1166,11 @@ static inline bool blk_mq_complete_need_ipi(struct request *rq)
if (force_irqthreads())
return false;
- /* same CPU or cache domain? Complete locally */
+ /* same CPU or cache domain and capacity? Complete locally */
if (cpu == rq->mq_ctx->cpu ||
(!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags) &&
- cpus_share_cache(cpu, rq->mq_ctx->cpu)))
+ cpus_share_cache(cpu, rq->mq_ctx->cpu) &&
+ cpus_equal_capacity(cpu, rq->mq_ctx->cpu)))
return false;
/* don't try to IPI to an offline CPU */
@@ -1254,7 +1254,7 @@ void blk_mq_start_request(struct request *rq)
if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags) &&
!blk_rq_is_passthrough(rq)) {
- rq->io_start_time_ns = ktime_get_ns();
+ rq->io_start_time_ns = blk_time_get_ns();
rq->stats_sectors = blk_rq_sectors(rq);
rq->rq_flags |= RQF_STATS;
rq_qos_issue(q, rq);
@@ -1409,22 +1409,10 @@ blk_status_t blk_execute_rq(struct request *rq, bool at_head)
blk_mq_insert_request(rq, at_head ? BLK_MQ_INSERT_AT_HEAD : 0);
blk_mq_run_hw_queue(hctx, false);
- if (blk_rq_is_poll(rq)) {
+ if (blk_rq_is_poll(rq))
blk_rq_poll_completion(rq, &wait.done);
- } else {
- /*
- * Prevent hang_check timer from firing at us during very long
- * I/O
- */
- unsigned long hang_check = sysctl_hung_task_timeout_secs;
-
- if (hang_check)
- while (!wait_for_completion_io_timeout(&wait.done,
- hang_check * (HZ/2)))
- ;
- else
- wait_for_completion_io(&wait.done);
- }
+ else
+ blk_wait_io(&wait.done);
return wait.ret;
}
@@ -2892,9 +2880,6 @@ static struct request *blk_mq_get_new_requests(struct request_queue *q,
};
struct request *rq;
- if (blk_mq_attempt_bio_merge(q, bio, nsegs))
- return NULL;
-
rq_qos_throttle(q, bio);
if (plug) {
@@ -2913,22 +2898,31 @@ static struct request *blk_mq_get_new_requests(struct request_queue *q,
}
/*
- * Check if we can use the passed on request for submitting the passed in bio,
- * and remove it from the request list if it can be used.
+ * Check if there is a suitable cached request and return it.
*/
-static bool blk_mq_use_cached_rq(struct request *rq, struct blk_plug *plug,
- struct bio *bio)
+static struct request *blk_mq_peek_cached_request(struct blk_plug *plug,
+ struct request_queue *q, blk_opf_t opf)
{
- enum hctx_type type = blk_mq_get_hctx_type(bio->bi_opf);
- enum hctx_type hctx_type = rq->mq_hctx->type;
+ enum hctx_type type = blk_mq_get_hctx_type(opf);
+ struct request *rq;
- WARN_ON_ONCE(rq_list_peek(&plug->cached_rq) != rq);
+ if (!plug)
+ return NULL;
+ rq = rq_list_peek(&plug->cached_rq);
+ if (!rq || rq->q != q)
+ return NULL;
+ if (type != rq->mq_hctx->type &&
+ (type != HCTX_TYPE_READ || rq->mq_hctx->type != HCTX_TYPE_DEFAULT))
+ return NULL;
+ if (op_is_flush(rq->cmd_flags) != op_is_flush(opf))
+ return NULL;
+ return rq;
+}
- if (type != hctx_type &&
- !(type == HCTX_TYPE_READ && hctx_type == HCTX_TYPE_DEFAULT))
- return false;
- if (op_is_flush(rq->cmd_flags) != op_is_flush(bio->bi_opf))
- return false;
+static void blk_mq_use_cached_rq(struct request *rq, struct blk_plug *plug,
+ struct bio *bio)
+{
+ WARN_ON_ONCE(rq_list_peek(&plug->cached_rq) != rq);
/*
* If any qos ->throttle() end up blocking, we will have flushed the
@@ -2941,7 +2935,6 @@ static bool blk_mq_use_cached_rq(struct request *rq, struct blk_plug *plug,
blk_mq_rq_time_init(rq, 0);
rq->cmd_flags = bio->bi_opf;
INIT_LIST_HEAD(&rq->queuelist);
- return true;
}
/**
@@ -2963,50 +2956,43 @@ void blk_mq_submit_bio(struct bio *bio)
struct blk_plug *plug = blk_mq_plug(bio);
const int is_sync = op_is_sync(bio->bi_opf);
struct blk_mq_hw_ctx *hctx;
- struct request *rq = NULL;
unsigned int nr_segs = 1;
+ struct request *rq;
blk_status_t ret;
bio = blk_queue_bounce(bio, q);
- if (plug) {
- rq = rq_list_peek(&plug->cached_rq);
- if (rq && rq->q != q)
- rq = NULL;
- }
- if (rq) {
- if (unlikely(bio_may_exceed_limits(bio, &q->limits))) {
- bio = __bio_split_to_limits(bio, &q->limits, &nr_segs);
- if (!bio)
- return;
- }
- if (!bio_integrity_prep(bio))
- return;
- if (blk_mq_attempt_bio_merge(q, bio, nr_segs))
- return;
- if (blk_mq_use_cached_rq(rq, plug, bio))
- goto done;
- percpu_ref_get(&q->q_usage_counter);
- } else {
+ /*
+ * If the plug has a cached request for this queue, try use it.
+ *
+ * The cached request already holds a q_usage_counter reference and we
+ * don't have to acquire a new one if we use it.
+ */
+ rq = blk_mq_peek_cached_request(plug, q, bio->bi_opf);
+ if (!rq) {
if (unlikely(bio_queue_enter(bio)))
return;
- if (unlikely(bio_may_exceed_limits(bio, &q->limits))) {
- bio = __bio_split_to_limits(bio, &q->limits, &nr_segs);
- if (!bio)
- goto fail;
- }
- if (!bio_integrity_prep(bio))
- goto fail;
}
- rq = blk_mq_get_new_requests(q, plug, bio, nr_segs);
- if (unlikely(!rq)) {
-fail:
- blk_queue_exit(q);
- return;
+ if (unlikely(bio_may_exceed_limits(bio, &q->limits))) {
+ bio = __bio_split_to_limits(bio, &q->limits, &nr_segs);
+ if (!bio)
+ goto queue_exit;
+ }
+ if (!bio_integrity_prep(bio))
+ goto queue_exit;
+
+ if (blk_mq_attempt_bio_merge(q, bio, nr_segs))
+ goto queue_exit;
+
+ if (!rq) {
+ rq = blk_mq_get_new_requests(q, plug, bio, nr_segs);
+ if (unlikely(!rq))
+ goto queue_exit;
+ } else {
+ blk_mq_use_cached_rq(rq, plug, bio);
}
-done:
trace_block_getrq(bio);
rq_qos_track(q, rq, bio);
@@ -3037,6 +3023,15 @@ done:
} else {
blk_mq_run_dispatch_ops(q, blk_mq_try_issue_directly(hctx, rq));
}
+ return;
+
+queue_exit:
+ /*
+ * Don't drop the queue reference if we were trying to use a cached
+ * request and thus didn't acquire one.
+ */
+ if (!rq)
+ blk_queue_exit(q);
}
#ifdef CONFIG_BLK_MQ_STACKING
@@ -3098,7 +3093,7 @@ blk_status_t blk_insert_cloned_request(struct request *rq)
blk_mq_run_dispatch_ops(q,
ret = blk_mq_request_issue_directly(rq, true));
if (ret)
- blk_account_io_done(rq, ktime_get_ns());
+ blk_account_io_done(rq, blk_time_get_ns());
return ret;
}
EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
@@ -4078,15 +4073,16 @@ void blk_mq_release(struct request_queue *q)
blk_mq_sysfs_deinit(q);
}
-static struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set,
- void *queuedata)
+struct request_queue *blk_mq_alloc_queue(struct blk_mq_tag_set *set,
+ struct queue_limits *lim, void *queuedata)
{
+ struct queue_limits default_lim = { };
struct request_queue *q;
int ret;
- q = blk_alloc_queue(set->numa_node);
- if (!q)
- return ERR_PTR(-ENOMEM);
+ q = blk_alloc_queue(lim ? lim : &default_lim, set->numa_node);
+ if (IS_ERR(q))
+ return q;
q->queuedata = queuedata;
ret = blk_mq_init_allocated_queue(set, q);
if (ret) {
@@ -4095,20 +4091,15 @@ static struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set,
}
return q;
}
-
-struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
-{
- return blk_mq_init_queue_data(set, NULL);
-}
-EXPORT_SYMBOL(blk_mq_init_queue);
+EXPORT_SYMBOL(blk_mq_alloc_queue);
/**
* blk_mq_destroy_queue - shutdown a request queue
* @q: request queue to shutdown
*
- * This shuts down a request queue allocated by blk_mq_init_queue(). All future
+ * This shuts down a request queue allocated by blk_mq_alloc_queue(). All future
* requests will be failed with -ENODEV. The caller is responsible for dropping
- * the reference from blk_mq_init_queue() by calling blk_put_queue().
+ * the reference from blk_mq_alloc_queue() by calling blk_put_queue().
*
* Context: can sleep
*/
@@ -4129,13 +4120,14 @@ void blk_mq_destroy_queue(struct request_queue *q)
}
EXPORT_SYMBOL(blk_mq_destroy_queue);
-struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set, void *queuedata,
+struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set,
+ struct queue_limits *lim, void *queuedata,
struct lock_class_key *lkclass)
{
struct request_queue *q;
struct gendisk *disk;
- q = blk_mq_init_queue_data(set, queuedata);
+ q = blk_mq_alloc_queue(set, lim, queuedata);
if (IS_ERR(q))
return ERR_CAST(q);
@@ -4389,7 +4381,7 @@ static void blk_mq_update_queue_map(struct blk_mq_tag_set *set)
if (set->nr_maps == 1)
set->map[HCTX_TYPE_DEFAULT].nr_queues = set->nr_hw_queues;
- if (set->ops->map_queues && !is_kdump_kernel()) {
+ if (set->ops->map_queues) {
int i;
/*
@@ -4488,14 +4480,12 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
/*
* If a crashdump is active, then we are potentially in a very
- * memory constrained environment. Limit us to 1 queue and
- * 64 tags to prevent using too much memory.
+ * memory constrained environment. Limit us to 64 tags to prevent
+ * using too much memory.
*/
- if (is_kdump_kernel()) {
- set->nr_hw_queues = 1;
- set->nr_maps = 1;
+ if (is_kdump_kernel())
set->queue_depth = min(64U, set->queue_depth);
- }
+
/*
* There is no use for more h/w queues than cpus if we just have
* a single map
@@ -4525,7 +4515,7 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
GFP_KERNEL, set->numa_node);
if (!set->map[i].mq_map)
goto out_free_mq_map;
- set->map[i].nr_queues = is_kdump_kernel() ? 1 : set->nr_hw_queues;
+ set->map[i].nr_queues = set->nr_hw_queues;
}
blk_mq_update_queue_map(set);