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blk-mq: provide internal in-flight variant

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We don't have to inc/dec some counter, since we can just
iterate the tags. That makes inc/dec a noop, but means we
have to iterate busy tags to get an in-flight count.

Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2017-08-08 17:51:45 -06:00
parent 0609e0efc5
commit f299b7c7a9
4 changed files with 77 additions and 29 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

31
block/blk-mq.c
View file

@ -83,6 +83,37 @@ static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx,
sbitmap_clear_bit(&hctx->ctx_map, ctx->index_hw);
}
struct mq_inflight {
struct hd_struct *part;
unsigned int *inflight;
};
static void blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx,
struct request *rq, void *priv,
bool reserved)
{
struct mq_inflight *mi = priv;
if (test_bit(REQ_ATOM_STARTED, &rq->atomic_flags) &&
!test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags)) {
/*
* Count as inflight if it either matches the partition we
* asked for, or if it's the root
*/
if (rq->part == mi->part || mi->part->partno)
mi->inflight[0]++;
}
}
void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
unsigned int inflight[2])
{
struct mq_inflight mi = { .part = part, .inflight = inflight, };
inflight[0] = 0;
blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
}
void blk_freeze_queue_start(struct request_queue *q)
{
int freeze_depth;

3
block/blk-mq.h
View file

@ -133,4 +133,7 @@ static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
return hctx->nr_ctx && hctx->tags;
}
void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
unsigned int inflight[2]);
#endif

37
block/genhd.c
View file

@ -45,6 +45,43 @@ static void disk_add_events(struct gendisk *disk);
static void disk_del_events(struct gendisk *disk);
static void disk_release_events(struct gendisk *disk);
void part_inc_in_flight(struct request_queue *q, struct hd_struct *part, int rw)
{
if (q->mq_ops)
return;
atomic_inc(&part->in_flight[rw]);
if (part->partno)
atomic_inc(&part_to_disk(part)->part0.in_flight[rw]);
}
void part_dec_in_flight(struct request_queue *q, struct hd_struct *part, int rw)
{
if (q->mq_ops)
return;
atomic_dec(&part->in_flight[rw]);
if (part->partno)
atomic_dec(&part_to_disk(part)->part0.in_flight[rw]);
}
void part_in_flight(struct request_queue *q, struct hd_struct *part,
unsigned int inflight[2])
{
if (q->mq_ops) {
blk_mq_in_flight(q, part, inflight);
return;
}
inflight[0] = atomic_read(&part->in_flight[0]) +
atomic_read(&part->in_flight[1]);
if (part->partno) {
part = &part_to_disk(part)->part0;
inflight[1] = atomic_read(&part->in_flight[0]) +
atomic_read(&part->in_flight[1]);
}
}
/**
* disk_get_part - get partition
* @disk: disk to look partition from

35
include/linux/genhd.h
View file

@ -362,35 +362,12 @@ static inline void free_part_stats(struct hd_struct *part)
#define part_stat_sub(cpu, gendiskp, field, subnd) \
part_stat_add(cpu, gendiskp, field, -subnd)
static inline void part_inc_in_flight(struct request_queue *q,
struct hd_struct *part, int rw)
{
atomic_inc(&part->in_flight[rw]);
if (part->partno)
atomic_inc(&part_to_disk(part)->part0.in_flight[rw]);
}
static inline void part_dec_in_flight(struct request_queue *q,
struct hd_struct *part, int rw)
{
atomic_dec(&part->in_flight[rw]);
if (part->partno)
atomic_dec(&part_to_disk(part)->part0.in_flight[rw]);
}
static inline void part_in_flight(struct request_queue *q,
struct hd_struct *part,
unsigned int inflight[2])
{
inflight[0] = atomic_read(&part->in_flight[0]) +
atomic_read(&part->in_flight[1]);
if (part->partno) {
part = &part_to_disk(part)->part0;
inflight[1] = atomic_read(&part->in_flight[0]) +
atomic_read(&part->in_flight[1]);
} else
inflight[1] = 0;
}
void part_in_flight(struct request_queue *q, struct hd_struct *part,
unsigned int inflight[2]);
void part_dec_in_flight(struct request_queue *q, struct hd_struct *part,
int rw);
void part_inc_in_flight(struct request_queue *q, struct hd_struct *part,
int rw);
static inline struct partition_meta_info *alloc_part_info(struct gendisk *disk)
{