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blk-mq: move blk_mq_sched_insert_request to blk-mq.c

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blk_mq_sched_insert_request is the main request insert helper and not
directly I/O scheduler related.  Move blk_mq_sched_insert_request to
blk-mq.c, rename it to blk_mq_insert_request and mark it static.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230413064057.707578-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2023-04-13 08:40:43 +02:00 committed by Jens Axboe
parent 05a9311770
commit 2bd215df79
4 changed files with 82 additions and 83 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
block/blk-mq-sched.c
View File

@ -382,79 +382,6 @@ bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq,
}
EXPORT_SYMBOL_GPL(blk_mq_sched_try_insert_merge);
static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx,
struct request *rq)
{
/*
* dispatch flush and passthrough rq directly
*
* passthrough request has to be added to hctx->dispatch directly.
* For some reason, device may be in one situation which can't
* handle FS request, so STS_RESOURCE is always returned and the
* FS request will be added to hctx->dispatch. However passthrough
* request may be required at that time for fixing the problem. If
* passthrough request is added to scheduler queue, there isn't any
* chance to dispatch it given we prioritize requests in hctx->dispatch.
*/
if ((rq->rq_flags & RQF_FLUSH_SEQ) || blk_rq_is_passthrough(rq))
return true;
return false;
}
void blk_mq_sched_insert_request(struct request *rq, bool at_head,
bool run_queue, bool async)
{
struct request_queue *q = rq->q;
struct elevator_queue *e = q->elevator;
struct blk_mq_ctx *ctx = rq->mq_ctx;
struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
WARN_ON(e && (rq->tag != BLK_MQ_NO_TAG));
if (blk_mq_sched_bypass_insert(hctx, rq)) {
/*
* Firstly normal IO request is inserted to scheduler queue or
* sw queue, meantime we add flush request to dispatch queue(
* hctx->dispatch) directly and there is at most one in-flight
* flush request for each hw queue, so it doesn't matter to add
* flush request to tail or front of the dispatch queue.
*
* Secondly in case of NCQ, flush request belongs to non-NCQ
* command, and queueing it will fail when there is any
* in-flight normal IO request(NCQ command). When adding flush
* rq to the front of hctx->dispatch, it is easier to introduce
* extra time to flush rq's latency because of S_SCHED_RESTART
* compared with adding to the tail of dispatch queue, then
* chance of flush merge is increased, and less flush requests
* will be issued to controller. It is observed that ~10% time
* is saved in blktests block/004 on disk attached to AHCI/NCQ
* drive when adding flush rq to the front of hctx->dispatch.
*
* Simply queue flush rq to the front of hctx->dispatch so that
* intensive flush workloads can benefit in case of NCQ HW.
*/
at_head = (rq->rq_flags & RQF_FLUSH_SEQ) ? true : at_head;
blk_mq_request_bypass_insert(rq, at_head, false);
goto run;
}
if (e) {
LIST_HEAD(list);
list_add(&rq->queuelist, &list);
e->type->ops.insert_requests(hctx, &list, at_head);
} else {
spin_lock(&ctx->lock);
__blk_mq_insert_request(hctx, rq, at_head);
spin_unlock(&ctx->lock);
}
run:
if (run_queue)
blk_mq_run_hw_queue(hctx, async);
}
static int blk_mq_sched_alloc_map_and_rqs(struct request_queue *q,
struct blk_mq_hw_ctx *hctx,
unsigned int hctx_idx)

3
block/blk-mq-sched.h
View File

@ -16,9 +16,6 @@ bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq,
void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx);
void __blk_mq_sched_restart(struct blk_mq_hw_ctx *hctx);
void blk_mq_sched_insert_request(struct request *rq, bool at_head,
bool run_queue, bool async);
void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx);
int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e);

87
block/blk-mq.c
View File

@ -44,6 +44,8 @@
static DEFINE_PER_CPU(struct llist_head, blk_cpu_done);
static void blk_mq_insert_request(struct request *rq, bool at_head,
bool run_queue, bool async);
static void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
struct list_head *list);
@ -1303,7 +1305,7 @@ void blk_execute_rq_nowait(struct request *rq, bool at_head)
if (current->plug && !at_head)
blk_add_rq_to_plug(current->plug, rq);
else
blk_mq_sched_insert_request(rq, at_head, true, false);
blk_mq_insert_request(rq, at_head, true, false);
}
EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
@ -1364,7 +1366,7 @@ blk_status_t blk_execute_rq(struct request *rq, bool at_head)
rq->end_io = blk_end_sync_rq;
blk_account_io_start(rq);
blk_mq_sched_insert_request(rq, at_head, true, false);
blk_mq_insert_request(rq, at_head, true, false);
if (blk_rq_is_poll(rq)) {
blk_rq_poll_completion(rq, &wait.done);
@ -1438,13 +1440,13 @@ static void blk_mq_requeue_work(struct work_struct *work)
if (rq->rq_flags & RQF_DONTPREP)
blk_mq_request_bypass_insert(rq, false, false);
else
blk_mq_sched_insert_request(rq, true, false, false);
blk_mq_insert_request(rq, true, false, false);
}
while (!list_empty(&rq_list)) {
rq = list_entry(rq_list.next, struct request, queuelist);
list_del_init(&rq->queuelist);
blk_mq_sched_insert_request(rq, false, false, false);
blk_mq_insert_request(rq, false, false, false);
}
blk_mq_run_hw_queues(q, false);
@ -2532,6 +2534,79 @@ out:
blk_mq_run_hw_queue(hctx, run_queue_async);
}
static bool blk_mq_sched_bypass_insert(struct blk_mq_hw_ctx *hctx,
struct request *rq)
{
/*
* dispatch flush and passthrough rq directly
*
* passthrough request has to be added to hctx->dispatch directly.
* For some reason, device may be in one situation which can't
* handle FS request, so STS_RESOURCE is always returned and the
* FS request will be added to hctx->dispatch. However passthrough
* request may be required at that time for fixing the problem. If
* passthrough request is added to scheduler queue, there isn't any
* chance to dispatch it given we prioritize requests in hctx->dispatch.
*/
if ((rq->rq_flags & RQF_FLUSH_SEQ) || blk_rq_is_passthrough(rq))
return true;
return false;
}
static void blk_mq_insert_request(struct request *rq, bool at_head,
bool run_queue, bool async)
{
struct request_queue *q = rq->q;
struct elevator_queue *e = q->elevator;
struct blk_mq_ctx *ctx = rq->mq_ctx;
struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
WARN_ON(e && (rq->tag != BLK_MQ_NO_TAG));
if (blk_mq_sched_bypass_insert(hctx, rq)) {
/*
* Firstly normal IO request is inserted to scheduler queue or
* sw queue, meantime we add flush request to dispatch queue(
* hctx->dispatch) directly and there is at most one in-flight
* flush request for each hw queue, so it doesn't matter to add
* flush request to tail or front of the dispatch queue.
*
* Secondly in case of NCQ, flush request belongs to non-NCQ
* command, and queueing it will fail when there is any
* in-flight normal IO request(NCQ command). When adding flush
* rq to the front of hctx->dispatch, it is easier to introduce
* extra time to flush rq's latency because of S_SCHED_RESTART
* compared with adding to the tail of dispatch queue, then
* chance of flush merge is increased, and less flush requests
* will be issued to controller. It is observed that ~10% time
* is saved in blktests block/004 on disk attached to AHCI/NCQ
* drive when adding flush rq to the front of hctx->dispatch.
*
* Simply queue flush rq to the front of hctx->dispatch so that
* intensive flush workloads can benefit in case of NCQ HW.
*/
at_head = (rq->rq_flags & RQF_FLUSH_SEQ) ? true : at_head;
blk_mq_request_bypass_insert(rq, at_head, false);
goto run;
}
if (e) {
LIST_HEAD(list);
list_add(&rq->queuelist, &list);
e->type->ops.insert_requests(hctx, &list, at_head);
} else {
spin_lock(&ctx->lock);
__blk_mq_insert_request(hctx, rq, at_head);
spin_unlock(&ctx->lock);
}
run:
if (run_queue)
blk_mq_run_hw_queue(hctx, async);
}
static void blk_mq_bio_to_request(struct request *rq, struct bio *bio,
unsigned int nr_segs)
{
@ -2623,7 +2698,7 @@ insert:
if (bypass_insert)
return BLK_STS_RESOURCE;
blk_mq_sched_insert_request(rq, false, run_queue, false);
blk_mq_insert_request(rq, false, run_queue, false);
return BLK_STS_OK;
}
@ -2975,7 +3050,7 @@ void blk_mq_submit_bio(struct bio *bio)
else if ((rq->rq_flags & RQF_ELV) ||
(rq->mq_hctx->dispatch_busy &&
(q->nr_hw_queues == 1 || !is_sync)))
blk_mq_sched_insert_request(rq, false, true, true);
blk_mq_insert_request(rq, false, true, true);
else
blk_mq_run_dispatch_ops(rq->q,
blk_mq_try_issue_directly(rq->mq_hctx, rq));

2
block/mq-deadline.c
View File

@ -820,7 +820,7 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
}
/*
* Called from blk_mq_sched_insert_request() or blk_mq_dispatch_plug_list().
* Called from blk_mq_insert_request() or blk_mq_dispatch_plug_list().
*/
static void dd_insert_requests(struct blk_mq_hw_ctx *hctx,
struct list_head *list, bool at_head)