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Date: Wed, 7 Dec 2016 16:10:00 -0700
From: Jens Axboe <axboe@...com>
To: <axboe@...nel.dk>, <linux-block@...r.kernel.org>,
<linux-kernel@...r.kernel.org>
CC: <paolo.valente@...aro.org>, <osandov@...com>,
Jens Axboe <axboe@...com>
Subject: [PATCH 6/7] blk-mq-sched: add framework for MQ capable IO schedulers
Signed-off-by: Jens Axboe <axboe@...com>
---
block/Makefile | 2 +-
block/blk-core.c | 3 +-
block/blk-exec.c | 3 +-
block/blk-flush.c | 7 +--
block/blk-mq-tag.c | 1 +
block/blk-mq.c | 138 +++++++++++++++++++++++++----------------------
block/blk-mq.h | 32 +++++------
block/elevator.c | 132 ++++++++++++++++++++++++++++++++++-----------
include/linux/blk-mq.h | 2 +-
include/linux/elevator.h | 25 ++++++++-
10 files changed, 222 insertions(+), 123 deletions(-)
diff --git a/block/Makefile b/block/Makefile
index a827f988c4e6..2eee9e1bb6db 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -6,7 +6,7 @@ obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-tag.o blk-sysfs.o \
blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \
blk-lib.o blk-mq.o blk-mq-tag.o blk-stat.o \
- blk-mq-sysfs.o blk-mq-cpumap.o ioctl.o \
+ blk-mq-sysfs.o blk-mq-cpumap.o blk-mq-sched.o ioctl.o \
genhd.o scsi_ioctl.o partition-generic.o ioprio.o \
badblocks.o partitions/
diff --git a/block/blk-core.c b/block/blk-core.c
index 4b7ec5958055..a6163d9bb8a6 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -39,6 +39,7 @@
#include "blk.h"
#include "blk-mq.h"
+#include "blk-mq-sched.h"
#include "blk-wbt.h"
EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
@@ -2173,7 +2174,7 @@ int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
if (q->mq_ops) {
if (blk_queue_io_stat(q))
blk_account_io_start(rq, true);
- blk_mq_insert_request(rq, false, true, false);
+ blk_mq_sched_insert_request(rq, false, true, false);
return 0;
}
diff --git a/block/blk-exec.c b/block/blk-exec.c
index 3ecb00a6cf45..86656fdfa637 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -9,6 +9,7 @@
#include <linux/sched/sysctl.h>
#include "blk.h"
+#include "blk-mq-sched.h"
/*
* for max sense size
@@ -65,7 +66,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
* be reused after dying flag is set
*/
if (q->mq_ops) {
- blk_mq_insert_request(rq, at_head, true, false);
+ blk_mq_sched_insert_request(rq, at_head, true, false);
return;
}
diff --git a/block/blk-flush.c b/block/blk-flush.c
index 27a42dab5a36..63b91697d167 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -74,6 +74,7 @@
#include "blk.h"
#include "blk-mq.h"
#include "blk-mq-tag.h"
+#include "blk-mq-sched.h"
/* FLUSH/FUA sequences */
enum {
@@ -425,9 +426,9 @@ void blk_insert_flush(struct request *rq)
*/
if ((policy & REQ_FSEQ_DATA) &&
!(policy & (REQ_FSEQ_PREFLUSH | REQ_FSEQ_POSTFLUSH))) {
- if (q->mq_ops) {
- blk_mq_insert_request(rq, false, true, false);
- } else
+ if (q->mq_ops)
+ blk_mq_sched_insert_request(rq, false, true, false);
+ else
list_add_tail(&rq->queuelist, &q->queue_head);
return;
}
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index dcf5ce3ba4bf..bbd494e23d57 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -12,6 +12,7 @@
#include "blk.h"
#include "blk-mq.h"
#include "blk-mq-tag.h"
+#include "blk-mq-sched.h"
bool blk_mq_has_free_tags(struct blk_mq_tags *tags)
{
diff --git a/block/blk-mq.c b/block/blk-mq.c
index abbf7cca4d0d..102ef2945dfc 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -32,6 +32,7 @@
#include "blk-mq-tag.h"
#include "blk-stat.h"
#include "blk-wbt.h"
+#include "blk-mq-sched.h"
static DEFINE_MUTEX(all_q_mutex);
static LIST_HEAD(all_q_list);
@@ -41,7 +42,8 @@ static LIST_HEAD(all_q_list);
*/
static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx)
{
- return sbitmap_any_bit_set(&hctx->ctx_map);
+ return sbitmap_any_bit_set(&hctx->ctx_map) ||
+ blk_mq_sched_has_work(hctx);
}
/*
@@ -167,8 +169,8 @@ bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)
}
EXPORT_SYMBOL(blk_mq_can_queue);
-static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
- struct request *rq, unsigned int op)
+void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
+ struct request *rq, unsigned int op)
{
INIT_LIST_HEAD(&rq->queuelist);
/* csd/requeue_work/fifo_time is initialized before use */
@@ -214,8 +216,8 @@ static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
ctx->rq_dispatched[op_is_sync(op)]++;
}
-static struct request *
-__blk_mq_alloc_request(struct blk_mq_alloc_data *data, unsigned int op)
+struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data,
+ unsigned int op)
{
struct request *rq;
unsigned int tag;
@@ -319,12 +321,14 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw,
}
EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx);
-static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx,
- struct blk_mq_ctx *ctx, struct request *rq)
+void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
+ struct request *rq)
{
const int tag = rq->tag;
struct request_queue *q = rq->q;
+ blk_mq_sched_completed_request(hctx, rq);
+
if (rq->rq_flags & RQF_MQ_INFLIGHT)
atomic_dec(&hctx->nr_active);
@@ -467,6 +471,8 @@ void blk_mq_start_request(struct request *rq)
{
struct request_queue *q = rq->q;
+ blk_mq_sched_started_request(rq);
+
trace_block_rq_issue(q, rq);
rq->resid_len = blk_rq_bytes(rq);
@@ -515,6 +521,7 @@ static void __blk_mq_requeue_request(struct request *rq)
trace_block_rq_requeue(q, rq);
wbt_requeue(q->rq_wb, &rq->issue_stat);
+ blk_mq_sched_requeue_request(rq);
if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
if (q->dma_drain_size && blk_rq_bytes(rq))
@@ -549,13 +556,13 @@ static void blk_mq_requeue_work(struct work_struct *work)
rq->rq_flags &= ~RQF_SOFTBARRIER;
list_del_init(&rq->queuelist);
- blk_mq_insert_request(rq, true, false, false);
+ blk_mq_sched_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_insert_request(rq, false, false, false);
+ blk_mq_sched_insert_request(rq, false, false, false);
}
blk_mq_run_hw_queues(q, false);
@@ -761,8 +768,16 @@ static bool blk_mq_attempt_merge(struct request_queue *q,
if (!blk_rq_merge_ok(rq, bio))
continue;
+ if (!blk_mq_sched_allow_merge(q, rq, bio))
+ break;
el_ret = blk_try_merge(rq, bio);
+ if (el_ret == ELEVATOR_NO_MERGE)
+ continue;
+
+ if (!blk_mq_sched_allow_merge(q, rq, bio))
+ break;
+
if (el_ret == ELEVATOR_BACK_MERGE) {
if (bio_attempt_back_merge(q, rq, bio)) {
ctx->rq_merged++;
@@ -947,11 +962,17 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
if (!(hctx->flags & BLK_MQ_F_BLOCKING)) {
rcu_read_lock();
- blk_mq_process_rq_list(hctx);
+ if (hctx->queue->elevator)
+ blk_mq_sched_dispatch_requests(hctx);
+ else
+ blk_mq_process_rq_list(hctx);
rcu_read_unlock();
} else {
srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu);
- blk_mq_process_rq_list(hctx);
+ if (hctx->queue->elevator)
+ blk_mq_sched_dispatch_requests(hctx);
+ else
+ blk_mq_process_rq_list(hctx);
srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx);
}
}
@@ -1135,8 +1156,8 @@ static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
list_add_tail(&rq->queuelist, &ctx->rq_list);
}
-static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
- struct request *rq, bool at_head)
+void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
+ bool at_head)
{
struct blk_mq_ctx *ctx = rq->mq_ctx;
@@ -1144,21 +1165,6 @@ static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
blk_mq_hctx_mark_pending(hctx, ctx);
}
-void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue,
- bool async)
-{
- struct blk_mq_ctx *ctx = rq->mq_ctx;
- struct request_queue *q = rq->q;
- struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
-
- spin_lock(&ctx->lock);
- __blk_mq_insert_request(hctx, rq, at_head);
- spin_unlock(&ctx->lock);
-
- if (run_queue)
- blk_mq_run_hw_queue(hctx, async);
-}
-
static void blk_mq_insert_requests(struct request_queue *q,
struct blk_mq_ctx *ctx,
struct list_head *list,
@@ -1174,17 +1180,14 @@ static void blk_mq_insert_requests(struct request_queue *q,
* preemption doesn't flush plug list, so it's possible ctx->cpu is
* offline now
*/
- spin_lock(&ctx->lock);
while (!list_empty(list)) {
struct request *rq;
rq = list_first_entry(list, struct request, queuelist);
BUG_ON(rq->mq_ctx != ctx);
list_del_init(&rq->queuelist);
- __blk_mq_insert_req_list(hctx, rq, false);
+ blk_mq_sched_insert_request(rq, false, false, false);
}
- blk_mq_hctx_mark_pending(hctx, ctx);
- spin_unlock(&ctx->lock);
blk_mq_run_hw_queue(hctx, from_schedule);
}
@@ -1285,41 +1288,27 @@ static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx,
}
}
-static struct request *blk_mq_map_request(struct request_queue *q,
- struct bio *bio,
- struct blk_mq_alloc_data *data)
-{
- struct blk_mq_hw_ctx *hctx;
- struct blk_mq_ctx *ctx;
- struct request *rq;
-
- blk_queue_enter_live(q);
- ctx = blk_mq_get_ctx(q);
- hctx = blk_mq_map_queue(q, ctx->cpu);
-
- trace_block_getrq(q, bio, bio->bi_opf);
- blk_mq_set_alloc_data(data, q, 0, ctx, hctx);
- rq = __blk_mq_alloc_request(data, bio->bi_opf);
-
- data->hctx->queued++;
- return rq;
-}
-
static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie)
{
- int ret;
struct request_queue *q = rq->q;
- struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, rq->mq_ctx->cpu);
struct blk_mq_queue_data bd = {
.rq = rq,
.list = NULL,
.last = 1
};
- blk_qc_t new_cookie = blk_tag_to_qc_t(rq->tag, hctx->queue_num);
+ struct blk_mq_hw_ctx *hctx;
+ blk_qc_t new_cookie;
+ int ret;
+
+ if (q->elevator)
+ goto insert;
+ hctx = blk_mq_map_queue(q, rq->mq_ctx->cpu);
if (blk_mq_hctx_stopped(hctx))
goto insert;
+ new_cookie = blk_tag_to_qc_t(rq->tag, hctx->queue_num);
+
/*
* For OK queue, we are done. For error, kill it. Any other
* error (busy), just add it to our list as we previously
@@ -1341,7 +1330,7 @@ static void blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie)
}
insert:
- blk_mq_insert_request(rq, false, true, true);
+ blk_mq_sched_insert_request(rq, false, true, true);
}
/*
@@ -1374,9 +1363,14 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))
return BLK_QC_T_NONE;
+ if (blk_mq_sched_bio_merge(q, bio))
+ return BLK_QC_T_NONE;
+
wb_acct = wbt_wait(q->rq_wb, bio, NULL);
- rq = blk_mq_map_request(q, bio, &data);
+ trace_block_getrq(q, bio, bio->bi_opf);
+
+ rq = blk_mq_sched_get_request(q, bio, &data);
if (unlikely(!rq)) {
__wbt_done(q->rq_wb, wb_acct);
return BLK_QC_T_NONE;
@@ -1438,6 +1432,12 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
goto done;
}
+ if (q->elevator) {
+ blk_mq_put_ctx(data.ctx);
+ blk_mq_bio_to_request(rq, bio);
+ blk_mq_sched_insert_request(rq, false, true, true);
+ goto done;
+ }
if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
/*
* For a SYNC request, send it to the hardware immediately. For
@@ -1483,9 +1483,14 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
} else
request_count = blk_plug_queued_count(q);
+ if (blk_mq_sched_bio_merge(q, bio))
+ return BLK_QC_T_NONE;
+
wb_acct = wbt_wait(q->rq_wb, bio, NULL);
- rq = blk_mq_map_request(q, bio, &data);
+ trace_block_getrq(q, bio, bio->bi_opf);
+
+ rq = blk_mq_sched_get_request(q, bio, &data);
if (unlikely(!rq)) {
__wbt_done(q->rq_wb, wb_acct);
return BLK_QC_T_NONE;
@@ -1535,6 +1540,12 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
return cookie;
}
+ if (q->elevator) {
+ blk_mq_put_ctx(data.ctx);
+ blk_mq_bio_to_request(rq, bio);
+ blk_mq_sched_insert_request(rq, false, true, true);
+ goto done;
+ }
if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
/*
* For a SYNC request, send it to the hardware immediately. For
@@ -1547,15 +1558,16 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
}
blk_mq_put_ctx(data.ctx);
+done:
return cookie;
}
-static void blk_mq_free_rq_map(struct blk_mq_tag_set *set,
- struct blk_mq_tags *tags, unsigned int hctx_idx)
+void blk_mq_free_rq_map(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
+ unsigned int hctx_idx)
{
struct page *page;
- if (tags->rqs && set->ops->exit_request) {
+ if (tags->rqs && set && set->ops->exit_request) {
int i;
for (i = 0; i < tags->nr_tags; i++) {
@@ -1588,8 +1600,8 @@ static size_t order_to_size(unsigned int order)
return (size_t)PAGE_SIZE << order;
}
-static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
- unsigned int hctx_idx)
+struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
+ unsigned int hctx_idx)
{
struct blk_mq_tags *tags;
unsigned int i, j, entries_per_page, max_order = 4;
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 3a54dd32a6fc..9284b1e0bccb 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -84,26 +84,6 @@ static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
put_cpu();
}
-struct blk_mq_alloc_data {
- /* input parameter */
- struct request_queue *q;
- unsigned int flags;
-
- /* input & output parameter */
- struct blk_mq_ctx *ctx;
- struct blk_mq_hw_ctx *hctx;
-};
-
-static inline void blk_mq_set_alloc_data(struct blk_mq_alloc_data *data,
- struct request_queue *q, unsigned int flags,
- struct blk_mq_ctx *ctx, struct blk_mq_hw_ctx *hctx)
-{
- data->q = q;
- data->flags = flags;
- data->ctx = ctx;
- data->hctx = hctx;
-}
-
static inline bool blk_mq_hctx_stopped(struct blk_mq_hw_ctx *hctx)
{
return test_bit(BLK_MQ_S_STOPPED, &hctx->state);
@@ -114,4 +94,16 @@ static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx)
return hctx->nr_ctx && hctx->tags;
}
+void blk_mq_free_rq_map(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
+ unsigned int hctx_idx);
+struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
+ unsigned int hctx_idx);
+void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
+ struct request *rq, unsigned int op);
+void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
+ struct request *rq);
+struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data,
+ unsigned int op);
+void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
+ bool at_head);
#endif
diff --git a/block/elevator.c b/block/elevator.c
index 40f0c04e5ad3..d6d0f76bbe51 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -40,6 +40,7 @@
#include <trace/events/block.h>
#include "blk.h"
+#include "blk-mq-sched.h"
static DEFINE_SPINLOCK(elv_list_lock);
static LIST_HEAD(elv_list);
@@ -58,7 +59,9 @@ static int elv_iosched_allow_bio_merge(struct request *rq, struct bio *bio)
struct request_queue *q = rq->q;
struct elevator_queue *e = q->elevator;
- if (e->type->ops.elevator_allow_bio_merge_fn)
+ if (e->uses_mq && e->type->mq_ops.allow_merge)
+ return e->type->mq_ops.allow_merge(q, rq, bio);
+ else if (!e->uses_mq && e->type->ops.elevator_allow_bio_merge_fn)
return e->type->ops.elevator_allow_bio_merge_fn(q, rq, bio);
return 1;
@@ -224,7 +227,10 @@ int elevator_init(struct request_queue *q, char *name)
}
}
- err = e->ops.elevator_init_fn(q, e);
+ if (e->uses_mq)
+ err = e->mq_ops.init_sched(q, e);
+ else
+ err = e->ops.elevator_init_fn(q, e);
if (err)
elevator_put(e);
return err;
@@ -234,7 +240,9 @@ EXPORT_SYMBOL(elevator_init);
void elevator_exit(struct elevator_queue *e)
{
mutex_lock(&e->sysfs_lock);
- if (e->type->ops.elevator_exit_fn)
+ if (e->uses_mq && e->type->mq_ops.exit_sched)
+ e->type->mq_ops.exit_sched(e);
+ else if (!e->uses_mq && e->type->ops.elevator_exit_fn)
e->type->ops.elevator_exit_fn(e);
mutex_unlock(&e->sysfs_lock);
@@ -803,7 +811,8 @@ int elv_register_queue(struct request_queue *q)
}
kobject_uevent(&e->kobj, KOBJ_ADD);
e->registered = 1;
- if (e->type->ops.elevator_registered_fn)
+ e->uses_mq = q->mq_ops != NULL;
+ if (!e->uses_mq && e->type->ops.elevator_registered_fn)
e->type->ops.elevator_registered_fn(q);
}
return error;
@@ -891,9 +900,14 @@ EXPORT_SYMBOL_GPL(elv_unregister);
static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
{
struct elevator_queue *old = q->elevator;
- bool registered = old->registered;
+ bool old_registered = false;
int err;
+ if (q->mq_ops) {
+ blk_mq_freeze_queue(q);
+ blk_mq_quiesce_queue(q);
+ }
+
/*
* Turn on BYPASS and drain all requests w/ elevator private data.
* Block layer doesn't call into a quiesced elevator - all requests
@@ -901,32 +915,54 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
* using INSERT_BACK. All requests have SOFTBARRIER set and no
* merge happens either.
*/
- blk_queue_bypass_start(q);
+ if (old) {
+ old_registered = old->registered;
- /* unregister and clear all auxiliary data of the old elevator */
- if (registered)
- elv_unregister_queue(q);
+ if (!q->mq_ops)
+ blk_queue_bypass_start(q);
- spin_lock_irq(q->queue_lock);
- ioc_clear_queue(q);
- spin_unlock_irq(q->queue_lock);
+ /* unregister and clear all auxiliary data of the old elevator */
+ if (old_registered)
+ elv_unregister_queue(q);
+
+ if (q->queue_lock) {
+ spin_lock_irq(q->queue_lock);
+ ioc_clear_queue(q);
+ spin_unlock_irq(q->queue_lock);
+ }
+ }
/* allocate, init and register new elevator */
- err = new_e->ops.elevator_init_fn(q, new_e);
- if (err)
- goto fail_init;
+ if (new_e) {
+ if (new_e->uses_mq)
+ err = new_e->mq_ops.init_sched(q, new_e);
+ else
+ err = new_e->ops.elevator_init_fn(q, new_e);
+ if (err)
+ goto fail_init;
- if (registered) {
err = elv_register_queue(q);
if (err)
goto fail_register;
- }
+ } else
+ q->elevator = NULL;
/* done, kill the old one and finish */
- elevator_exit(old);
- blk_queue_bypass_end(q);
+ if (old) {
+ elevator_exit(old);
+ if (!q->mq_ops)
+ blk_queue_bypass_end(q);
+ }
+
+ if (q->mq_ops) {
+ blk_mq_unfreeze_queue(q);
+ blk_mq_start_stopped_hw_queues(q, true);
+ }
- blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
+ if (new_e)
+ blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
+ else
+ blk_add_trace_msg(q, "elv switch: none");
return 0;
@@ -934,9 +970,16 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
elevator_exit(q->elevator);
fail_init:
/* switch failed, restore and re-register old elevator */
- q->elevator = old;
- elv_register_queue(q);
- blk_queue_bypass_end(q);
+ if (old) {
+ q->elevator = old;
+ elv_register_queue(q);
+ if (!q->mq_ops)
+ blk_queue_bypass_end(q);
+ }
+ if (q->mq_ops) {
+ blk_mq_unfreeze_queue(q);
+ blk_mq_start_stopped_hw_queues(q, true);
+ }
return err;
}
@@ -949,8 +992,11 @@ static int __elevator_change(struct request_queue *q, const char *name)
char elevator_name[ELV_NAME_MAX];
struct elevator_type *e;
- if (!q->elevator)
- return -ENXIO;
+ /*
+ * Special case for mq, turn off scheduling
+ */
+ if (q->mq_ops && !strncmp(name, "none", 4))
+ return elevator_switch(q, NULL);
strlcpy(elevator_name, name, sizeof(elevator_name));
e = elevator_get(strstrip(elevator_name), true);
@@ -959,11 +1005,23 @@ static int __elevator_change(struct request_queue *q, const char *name)
return -EINVAL;
}
- if (!strcmp(elevator_name, q->elevator->type->elevator_name)) {
+ if (q->elevator &&
+ !strcmp(elevator_name, q->elevator->type->elevator_name)) {
elevator_put(e);
return 0;
}
+ if (!e->uses_mq && q->mq_ops) {
+ printk(KERN_ERR "blk-mq-sched: elv %s does not support mq\n", elevator_name);
+ elevator_put(e);
+ return -EINVAL;
+ }
+ if (e->uses_mq && !q->mq_ops) {
+ printk(KERN_ERR "blk-mq-sched: elv %s is for mq\n", elevator_name);
+ elevator_put(e);
+ return -EINVAL;
+ }
+
return elevator_switch(q, e);
}
@@ -985,7 +1043,7 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name,
{
int ret;
- if (!q->elevator)
+ if (!q->mq_ops || q->request_fn)
return count;
ret = __elevator_change(q, name);
@@ -999,24 +1057,34 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name,
ssize_t elv_iosched_show(struct request_queue *q, char *name)
{
struct elevator_queue *e = q->elevator;
- struct elevator_type *elv;
+ struct elevator_type *elv = NULL;
struct elevator_type *__e;
int len = 0;
- if (!q->elevator || !blk_queue_stackable(q))
+ if (!blk_queue_stackable(q))
return sprintf(name, "none\n");
- elv = e->type;
+ if (!q->elevator)
+ len += sprintf(name+len, "[none] ");
+ else
+ elv = e->type;
spin_lock(&elv_list_lock);
list_for_each_entry(__e, &elv_list, list) {
- if (!strcmp(elv->elevator_name, __e->elevator_name))
+ if (elv && !strcmp(elv->elevator_name, __e->elevator_name)) {
len += sprintf(name+len, "[%s] ", elv->elevator_name);
- else
+ continue;
+ }
+ if (__e->uses_mq && q->mq_ops)
+ len += sprintf(name+len, "%s ", __e->elevator_name);
+ else if (!__e->uses_mq && !q->mq_ops)
len += sprintf(name+len, "%s ", __e->elevator_name);
}
spin_unlock(&elv_list_lock);
+ if (q->mq_ops && q->elevator)
+ len += sprintf(name+len, "none");
+
len += sprintf(len+name, "\n");
return len;
}
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 87e404aae267..c86b314dde97 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -22,6 +22,7 @@ struct blk_mq_hw_ctx {
unsigned long flags; /* BLK_MQ_F_* flags */
+ void *sched_data;
struct request_queue *queue;
struct blk_flush_queue *fq;
@@ -179,7 +180,6 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
-void blk_mq_insert_request(struct request *, bool, bool, bool);
void blk_mq_free_request(struct request *rq);
void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *, struct request *rq);
bool blk_mq_can_queue(struct blk_mq_hw_ctx *);
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index b276e9ef0e0b..b270b1f75767 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -77,6 +77,24 @@ struct elevator_ops
elevator_registered_fn *elevator_registered_fn;
};
+struct blk_mq_alloc_data;
+struct blk_mq_hw_ctx;
+
+struct elevator_mq_ops {
+ int (*init_sched)(struct request_queue *, struct elevator_type *);
+ void (*exit_sched)(struct elevator_queue *);
+
+ bool (*allow_merge)(struct request_queue *, struct request *, struct bio *);
+ bool (*bio_merge)(struct blk_mq_hw_ctx *, struct bio *);
+ struct request *(*get_request)(struct request_queue *, struct bio *, struct blk_mq_alloc_data *);
+ void (*insert_request)(struct blk_mq_hw_ctx *, struct request *, bool);
+ struct request *(*dispatch_request)(struct blk_mq_hw_ctx *);
+ bool (*has_work)(struct blk_mq_hw_ctx *);
+ void (*completed_request)(struct blk_mq_hw_ctx *, struct request *);
+ void (*started_request)(struct request *);
+ void (*requeue_request)(struct request *);
+};
+
#define ELV_NAME_MAX (16)
struct elv_fs_entry {
@@ -94,12 +112,16 @@ struct elevator_type
struct kmem_cache *icq_cache;
/* fields provided by elevator implementation */
- struct elevator_ops ops;
+ union {
+ struct elevator_ops ops;
+ struct elevator_mq_ops mq_ops;
+ };
size_t icq_size; /* see iocontext.h */
size_t icq_align; /* ditto */
struct elv_fs_entry *elevator_attrs;
char elevator_name[ELV_NAME_MAX];
struct module *elevator_owner;
+ bool uses_mq;
/* managed by elevator core */
char icq_cache_name[ELV_NAME_MAX + 5]; /* elvname + "_io_cq" */
@@ -123,6 +145,7 @@ struct elevator_queue
struct kobject kobj;
struct mutex sysfs_lock;
unsigned int registered:1;
+ unsigned int uses_mq:1;
DECLARE_HASHTABLE(hash, ELV_HASH_BITS);
};
--
2.7.4
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