* [PATCH 1/5] blk-mq-sched: refactor scheduler initialization
2017-04-03 21:42 [PATCH 0/5] blk-mq: scheduler and hw queue initialization fixes/enhancements Omar Sandoval
@ 2017-04-03 21:42 ` Omar Sandoval
2017-04-03 21:42 ` [PATCH 2/5] blk-mq-sched: set up scheduler tags when bringing up new queues Omar Sandoval
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Omar Sandoval @ 2017-04-03 21:42 UTC (permalink / raw)
To: Jens Axboe, linux-block; +Cc: kernel-team
From: Omar Sandoval <osandov@fb.com>
Preparation cleanup for the next couple of fixes, push
blk_mq_sched_setup() and e->ops.mq.init_sched() into a helper.
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
block/blk-mq-sched.c | 82 ++++++++++++++++++++++++++++------------------------
block/blk-mq-sched.h | 2 +-
block/elevator.c | 32 ++++++++------------
3 files changed, 57 insertions(+), 59 deletions(-)
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 09af8ff18719..e08ba915343e 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -431,11 +431,45 @@ static void blk_mq_sched_free_tags(struct blk_mq_tag_set *set,
}
}
-int blk_mq_sched_setup(struct request_queue *q)
+static int blk_mq_sched_alloc_tags(struct request_queue *q,
+ struct blk_mq_hw_ctx *hctx,
+ unsigned int hctx_idx)
+{
+ struct blk_mq_tag_set *set = q->tag_set;
+ int ret;
+
+ hctx->sched_tags = blk_mq_alloc_rq_map(set, hctx_idx, q->nr_requests,
+ set->reserved_tags);
+ if (!hctx->sched_tags)
+ return -ENOMEM;
+
+ ret = blk_mq_alloc_rqs(set, hctx->sched_tags, hctx_idx, q->nr_requests);
+ if (ret)
+ blk_mq_sched_free_tags(set, hctx, hctx_idx);
+
+ return ret;
+}
+
+void blk_mq_sched_teardown(struct request_queue *q)
{
struct blk_mq_tag_set *set = q->tag_set;
struct blk_mq_hw_ctx *hctx;
- int ret, i;
+ int i;
+
+ queue_for_each_hw_ctx(q, hctx, i)
+ blk_mq_sched_free_tags(set, hctx, i);
+}
+
+int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
+{
+ struct blk_mq_hw_ctx *hctx;
+ unsigned int i;
+ int ret;
+
+ if (!e) {
+ q->elevator = NULL;
+ return 0;
+ }
/*
* Default to 256, since we don't split into sync/async like the
@@ -443,49 +477,21 @@ int blk_mq_sched_setup(struct request_queue *q)
*/
q->nr_requests = 2 * BLKDEV_MAX_RQ;
- /*
- * We're switching to using an IO scheduler, so setup the hctx
- * scheduler tags and switch the request map from the regular
- * tags to scheduler tags. First allocate what we need, so we
- * can safely fail and fallback, if needed.
- */
- ret = 0;
queue_for_each_hw_ctx(q, hctx, i) {
- hctx->sched_tags = blk_mq_alloc_rq_map(set, i,
- q->nr_requests, set->reserved_tags);
- if (!hctx->sched_tags) {
- ret = -ENOMEM;
- break;
- }
- ret = blk_mq_alloc_rqs(set, hctx->sched_tags, i, q->nr_requests);
+ ret = blk_mq_sched_alloc_tags(q, hctx, i);
if (ret)
- break;
+ goto err;
}
- /*
- * If we failed, free what we did allocate
- */
- if (ret) {
- queue_for_each_hw_ctx(q, hctx, i) {
- if (!hctx->sched_tags)
- continue;
- blk_mq_sched_free_tags(set, hctx, i);
- }
-
- return ret;
- }
+ ret = e->ops.mq.init_sched(q, e);
+ if (ret)
+ goto err;
return 0;
-}
-void blk_mq_sched_teardown(struct request_queue *q)
-{
- struct blk_mq_tag_set *set = q->tag_set;
- struct blk_mq_hw_ctx *hctx;
- int i;
-
- queue_for_each_hw_ctx(q, hctx, i)
- blk_mq_sched_free_tags(set, hctx, i);
+err:
+ blk_mq_sched_teardown(q);
+ return ret;
}
int blk_mq_sched_init(struct request_queue *q)
diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h
index a75b16b123f7..873f9af5a35b 100644
--- a/block/blk-mq-sched.h
+++ b/block/blk-mq-sched.h
@@ -32,7 +32,7 @@ void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx,
struct list_head *rq_list,
struct request *(*get_rq)(struct blk_mq_hw_ctx *));
-int blk_mq_sched_setup(struct request_queue *q);
+int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e);
void blk_mq_sched_teardown(struct request_queue *q);
int blk_mq_sched_init(struct request_queue *q);
diff --git a/block/elevator.c b/block/elevator.c
index 01139f549b5b..f236ef1d2be9 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -242,17 +242,12 @@ int elevator_init(struct request_queue *q, char *name)
}
}
- if (e->uses_mq) {
- err = blk_mq_sched_setup(q);
- if (!err)
- err = e->ops.mq.init_sched(q, e);
- } else
+ if (e->uses_mq)
+ err = blk_mq_init_sched(q, e);
+ else
err = e->ops.sq.elevator_init_fn(q, e);
- if (err) {
- if (e->uses_mq)
- blk_mq_sched_teardown(q);
+ if (err)
elevator_put(e);
- }
return err;
}
EXPORT_SYMBOL(elevator_init);
@@ -987,21 +982,18 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
}
/* allocate, init and register new elevator */
- if (new_e) {
- if (new_e->uses_mq) {
- err = blk_mq_sched_setup(q);
- if (!err)
- err = new_e->ops.mq.init_sched(q, new_e);
- } else
- err = new_e->ops.sq.elevator_init_fn(q, new_e);
- if (err)
- goto fail_init;
+ if (q->mq_ops)
+ err = blk_mq_init_sched(q, new_e);
+ else
+ err = new_e->ops.sq.elevator_init_fn(q, new_e);
+ if (err)
+ goto fail_init;
+ if (new_e) {
err = elv_register_queue(q);
if (err)
goto fail_register;
- } else
- q->elevator = NULL;
+ }
/* done, kill the old one and finish */
if (old) {
--
2.12.2
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 2/5] blk-mq-sched: set up scheduler tags when bringing up new queues
2017-04-03 21:42 [PATCH 0/5] blk-mq: scheduler and hw queue initialization fixes/enhancements Omar Sandoval
2017-04-03 21:42 ` [PATCH 1/5] blk-mq-sched: refactor scheduler initialization Omar Sandoval
@ 2017-04-03 21:42 ` Omar Sandoval
2017-04-03 21:42 ` [PATCH 3/5] blk-mq-sched: fix crash in switch error path Omar Sandoval
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Omar Sandoval @ 2017-04-03 21:42 UTC (permalink / raw)
To: Jens Axboe, linux-block; +Cc: kernel-team
From: Omar Sandoval <osandov@fb.com>
If a new hardware queue is added at runtime, we don't allocate scheduler
tags for it, leading to a crash. This hooks up the scheduler framework
to blk_mq_{init,exit}_hctx() to make sure everything gets properly
initialized/freed.
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
block/blk-mq-sched.c | 22 ++++++++++++++++++++++
block/blk-mq-sched.h | 5 +++++
block/blk-mq.c | 9 ++++++++-
3 files changed, 35 insertions(+), 1 deletion(-)
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index e08ba915343e..3fd918bb13a2 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -460,6 +460,28 @@ void blk_mq_sched_teardown(struct request_queue *q)
blk_mq_sched_free_tags(set, hctx, i);
}
+int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
+ unsigned int hctx_idx)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (!e)
+ return 0;
+
+ return blk_mq_sched_alloc_tags(q, hctx, hctx_idx);
+}
+
+void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
+ unsigned int hctx_idx)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (!e)
+ return;
+
+ blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx);
+}
+
int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
{
struct blk_mq_hw_ctx *hctx;
diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h
index 873f9af5a35b..19db25e0c95a 100644
--- a/block/blk-mq-sched.h
+++ b/block/blk-mq-sched.h
@@ -35,6 +35,11 @@ void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx,
int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e);
void blk_mq_sched_teardown(struct request_queue *q);
+int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
+ unsigned int hctx_idx);
+void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
+ unsigned int hctx_idx);
+
int blk_mq_sched_init(struct request_queue *q);
static inline bool
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 061fc2cc88d3..ac830cb488d7 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1839,6 +1839,8 @@ static void blk_mq_exit_hctx(struct request_queue *q,
hctx->fq->flush_rq, hctx_idx,
flush_start_tag + hctx_idx);
+ blk_mq_sched_exit_hctx(q, hctx, hctx_idx);
+
if (set->ops->exit_hctx)
set->ops->exit_hctx(hctx, hctx_idx);
@@ -1905,9 +1907,12 @@ static int blk_mq_init_hctx(struct request_queue *q,
set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
goto free_bitmap;
+ if (blk_mq_sched_init_hctx(q, hctx, hctx_idx))
+ goto exit_hctx;
+
hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size);
if (!hctx->fq)
- goto exit_hctx;
+ goto sched_exit_hctx;
if (set->ops->init_request &&
set->ops->init_request(set->driver_data,
@@ -1922,6 +1927,8 @@ static int blk_mq_init_hctx(struct request_queue *q,
free_fq:
kfree(hctx->fq);
+ sched_exit_hctx:
+ blk_mq_sched_exit_hctx(q, hctx, hctx_idx);
exit_hctx:
if (set->ops->exit_hctx)
set->ops->exit_hctx(hctx, hctx_idx);
--
2.12.2
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 3/5] blk-mq-sched: fix crash in switch error path
2017-04-03 21:42 [PATCH 0/5] blk-mq: scheduler and hw queue initialization fixes/enhancements Omar Sandoval
2017-04-03 21:42 ` [PATCH 1/5] blk-mq-sched: refactor scheduler initialization Omar Sandoval
2017-04-03 21:42 ` [PATCH 2/5] blk-mq-sched: set up scheduler tags when bringing up new queues Omar Sandoval
@ 2017-04-03 21:42 ` Omar Sandoval
2017-04-03 21:42 ` [PATCH 4/5] blk-mq: remap queues when adding/removing hardware queues Omar Sandoval
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Omar Sandoval @ 2017-04-03 21:42 UTC (permalink / raw)
To: Jens Axboe, linux-block; +Cc: kernel-team
From: Omar Sandoval <osandov@fb.com>
In elevator_switch(), if blk_mq_init_sched() fails, we attempt to fall
back to the original scheduler. However, at this point, we've already
torn down the original scheduler's tags, so this causes a crash. Doing
the fallback like the legacy elevator path is much harder for mq, so fix
it by just falling back to none, instead.
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
block/blk-mq-sched.c | 13 +++++--
block/blk-mq-sched.h | 2 +-
block/blk-mq.c | 2 --
block/blk-sysfs.c | 2 +-
block/elevator.c | 94 +++++++++++++++++++++++++++---------------------
include/linux/elevator.h | 2 +-
6 files changed, 67 insertions(+), 48 deletions(-)
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 3fd918bb13a2..63281fe34090 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -450,7 +450,7 @@ static int blk_mq_sched_alloc_tags(struct request_queue *q,
return ret;
}
-void blk_mq_sched_teardown(struct request_queue *q)
+static void blk_mq_sched_tags_teardown(struct request_queue *q)
{
struct blk_mq_tag_set *set = q->tag_set;
struct blk_mq_hw_ctx *hctx;
@@ -512,10 +512,19 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
return 0;
err:
- blk_mq_sched_teardown(q);
+ blk_mq_sched_tags_teardown(q);
+ q->elevator = NULL;
return ret;
}
+void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e)
+{
+ if (e->type->ops.mq.exit_sched)
+ e->type->ops.mq.exit_sched(e);
+ blk_mq_sched_tags_teardown(q);
+ q->elevator = NULL;
+}
+
int blk_mq_sched_init(struct request_queue *q)
{
int ret;
diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h
index 19db25e0c95a..e704956e0862 100644
--- a/block/blk-mq-sched.h
+++ b/block/blk-mq-sched.h
@@ -33,7 +33,7 @@ void blk_mq_sched_move_to_dispatch(struct blk_mq_hw_ctx *hctx,
struct request *(*get_rq)(struct blk_mq_hw_ctx *));
int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e);
-void blk_mq_sched_teardown(struct request_queue *q);
+void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e);
int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
unsigned int hctx_idx);
diff --git a/block/blk-mq.c b/block/blk-mq.c
index ac830cb488d7..477951d10cc9 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2153,8 +2153,6 @@ void blk_mq_release(struct request_queue *q)
struct blk_mq_hw_ctx *hctx;
unsigned int i;
- blk_mq_sched_teardown(q);
-
/* hctx kobj stays in hctx */
queue_for_each_hw_ctx(q, hctx, i) {
if (!hctx)
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 45854266e398..c47db43a40cc 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -803,7 +803,7 @@ static void blk_release_queue(struct kobject *kobj)
if (q->elevator) {
ioc_clear_queue(q);
- elevator_exit(q->elevator);
+ elevator_exit(q, q->elevator);
}
blk_free_queue_stats(q->stats);
diff --git a/block/elevator.c b/block/elevator.c
index f236ef1d2be9..dbeecf7be719 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -252,11 +252,11 @@ int elevator_init(struct request_queue *q, char *name)
}
EXPORT_SYMBOL(elevator_init);
-void elevator_exit(struct elevator_queue *e)
+void elevator_exit(struct request_queue *q, struct elevator_queue *e)
{
mutex_lock(&e->sysfs_lock);
if (e->uses_mq && e->type->ops.mq.exit_sched)
- e->type->ops.mq.exit_sched(e);
+ blk_mq_exit_sched(q, e);
else if (!e->uses_mq && e->type->ops.sq.elevator_exit_fn)
e->type->ops.sq.elevator_exit_fn(e);
mutex_unlock(&e->sysfs_lock);
@@ -941,6 +941,45 @@ void elv_unregister(struct elevator_type *e)
}
EXPORT_SYMBOL_GPL(elv_unregister);
+static int elevator_switch_mq(struct request_queue *q,
+ struct elevator_type *new_e)
+{
+ int ret;
+
+ blk_mq_freeze_queue(q);
+ blk_mq_quiesce_queue(q);
+
+ if (q->elevator) {
+ if (q->elevator->registered)
+ elv_unregister_queue(q);
+ ioc_clear_queue(q);
+ elevator_exit(q, q->elevator);
+ }
+
+ ret = blk_mq_init_sched(q, new_e);
+ if (ret)
+ goto out;
+
+ if (new_e) {
+ ret = elv_register_queue(q);
+ if (ret) {
+ elevator_exit(q, q->elevator);
+ goto out;
+ }
+ }
+
+ if (new_e)
+ blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
+ else
+ blk_add_trace_msg(q, "elv switch: none");
+
+out:
+ blk_mq_unfreeze_queue(q);
+ blk_mq_start_stopped_hw_queues(q, true);
+ return ret;
+
+}
+
/*
* switch to new_e io scheduler. be careful not to introduce deadlocks -
* we don't free the old io scheduler, before we have allocated what we
@@ -953,10 +992,8 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
bool old_registered = false;
int err;
- if (q->mq_ops) {
- blk_mq_freeze_queue(q);
- blk_mq_quiesce_queue(q);
- }
+ if (q->mq_ops)
+ return elevator_switch_mq(q, new_e);
/*
* Turn on BYPASS and drain all requests w/ elevator private data.
@@ -968,11 +1005,7 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
if (old) {
old_registered = old->registered;
- if (old->uses_mq)
- blk_mq_sched_teardown(q);
-
- if (!q->mq_ops)
- blk_queue_bypass_start(q);
+ blk_queue_bypass_start(q);
/* unregister and clear all auxiliary data of the old elevator */
if (old_registered)
@@ -982,53 +1015,32 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
}
/* allocate, init and register new elevator */
- if (q->mq_ops)
- err = blk_mq_init_sched(q, new_e);
- else
- err = new_e->ops.sq.elevator_init_fn(q, new_e);
+ err = new_e->ops.sq.elevator_init_fn(q, new_e);
if (err)
goto fail_init;
- if (new_e) {
- err = elv_register_queue(q);
- if (err)
- goto fail_register;
- }
+ err = elv_register_queue(q);
+ if (err)
+ goto fail_register;
/* done, kill the old one and finish */
if (old) {
- elevator_exit(old);
- if (!q->mq_ops)
- blk_queue_bypass_end(q);
+ elevator_exit(q, old);
+ blk_queue_bypass_end(q);
}
- if (q->mq_ops) {
- blk_mq_unfreeze_queue(q);
- blk_mq_start_stopped_hw_queues(q, true);
- }
-
- if (new_e)
- blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
- else
- blk_add_trace_msg(q, "elv switch: none");
+ blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
return 0;
fail_register:
- if (q->mq_ops)
- blk_mq_sched_teardown(q);
- elevator_exit(q->elevator);
+ elevator_exit(q, q->elevator);
fail_init:
/* switch failed, restore and re-register old elevator */
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);
+ blk_queue_bypass_end(q);
}
return err;
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index aebecc4ed088..22d39e8d4de1 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -211,7 +211,7 @@ extern ssize_t elv_iosched_show(struct request_queue *, char *);
extern ssize_t elv_iosched_store(struct request_queue *, const char *, size_t);
extern int elevator_init(struct request_queue *, char *);
-extern void elevator_exit(struct elevator_queue *);
+extern void elevator_exit(struct request_queue *, struct elevator_queue *);
extern int elevator_change(struct request_queue *, const char *);
extern bool elv_bio_merge_ok(struct request *, struct bio *);
extern struct elevator_queue *elevator_alloc(struct request_queue *,
--
2.12.2
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 4/5] blk-mq: remap queues when adding/removing hardware queues
2017-04-03 21:42 [PATCH 0/5] blk-mq: scheduler and hw queue initialization fixes/enhancements Omar Sandoval
` (2 preceding siblings ...)
2017-04-03 21:42 ` [PATCH 3/5] blk-mq-sched: fix crash in switch error path Omar Sandoval
@ 2017-04-03 21:42 ` Omar Sandoval
2017-04-03 21:42 ` [PATCH 5/5] blk-mq-sched: provide hooks for initializing hardware queue data Omar Sandoval
2017-04-04 17:09 ` [PATCH 0/5] blk-mq: scheduler and hw queue initialization fixes/enhancements Josef Bacik
5 siblings, 0 replies; 7+ messages in thread
From: Omar Sandoval @ 2017-04-03 21:42 UTC (permalink / raw)
To: Jens Axboe, linux-block; +Cc: kernel-team
From: Omar Sandoval <osandov@fb.com>
blk_mq_update_nr_hw_queues() used to remap hardware queues, which is the
behavior that drivers expect. However, commit 4e68a011428a changed
blk_mq_queue_reinit() to not remap queues for the case of CPU
hotplugging, inadvertently making blk_mq_update_nr_hw_queues() not remap
queues as well. This breaks, for example, NBD's multi-connection mode,
leaving the added hardware queues unused. Fix it by making
blk_mq_update_nr_hw_queues() explicitly remap the queues.
Fixes: 4e68a011428a ("blk-mq: don't redistribute hardware queues on a CPU hotplug event")
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
block/blk-mq.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 477951d10cc9..b49fdfde7e06 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2483,6 +2483,14 @@ static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
return 0;
}
+static int blk_mq_update_queue_map(struct blk_mq_tag_set *set)
+{
+ if (set->ops->map_queues)
+ return set->ops->map_queues(set);
+ else
+ return blk_mq_map_queues(set);
+}
+
/*
* Alloc a tag set to be associated with one or more request queues.
* May fail with EINVAL for various error conditions. May adjust the
@@ -2537,10 +2545,7 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
if (!set->mq_map)
goto out_free_tags;
- if (set->ops->map_queues)
- ret = set->ops->map_queues(set);
- else
- ret = blk_mq_map_queues(set);
+ ret = blk_mq_update_queue_map(set);
if (ret)
goto out_free_mq_map;
@@ -2632,6 +2637,7 @@ void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
blk_mq_freeze_queue(q);
set->nr_hw_queues = nr_hw_queues;
+ blk_mq_update_queue_map(set);
list_for_each_entry(q, &set->tag_list, tag_set_list) {
blk_mq_realloc_hw_ctxs(set, q);
blk_mq_queue_reinit(q, cpu_online_mask);
--
2.12.2
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 5/5] blk-mq-sched: provide hooks for initializing hardware queue data
2017-04-03 21:42 [PATCH 0/5] blk-mq: scheduler and hw queue initialization fixes/enhancements Omar Sandoval
` (3 preceding siblings ...)
2017-04-03 21:42 ` [PATCH 4/5] blk-mq: remap queues when adding/removing hardware queues Omar Sandoval
@ 2017-04-03 21:42 ` Omar Sandoval
2017-04-04 17:09 ` [PATCH 0/5] blk-mq: scheduler and hw queue initialization fixes/enhancements Josef Bacik
5 siblings, 0 replies; 7+ messages in thread
From: Omar Sandoval @ 2017-04-03 21:42 UTC (permalink / raw)
To: Jens Axboe, linux-block; +Cc: kernel-team
From: Omar Sandoval <osandov@fb.com>
Schedulers need to be informed when a hardware queue is added or removed
at runtime so they can allocate/free per-hardware queue data. So,
replace the blk_mq_sched_init_hctx_data() helper, which only makes sense
at init time, with .init_hctx() and .exit_hctx() hooks.
Signed-off-by: Omar Sandoval <osandov@fb.com>
---
block/blk-mq-sched.c | 81 +++++++++++++++++++++++++-----------------------
block/blk-mq-sched.h | 4 ---
include/linux/elevator.h | 2 ++
3 files changed, 45 insertions(+), 42 deletions(-)
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 63281fe34090..435f91bc724f 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -30,43 +30,6 @@ void blk_mq_sched_free_hctx_data(struct request_queue *q,
}
EXPORT_SYMBOL_GPL(blk_mq_sched_free_hctx_data);
-int blk_mq_sched_init_hctx_data(struct request_queue *q, size_t size,
- int (*init)(struct blk_mq_hw_ctx *),
- void (*exit)(struct blk_mq_hw_ctx *))
-{
- struct blk_mq_hw_ctx *hctx;
- int ret;
- int i;
-
- queue_for_each_hw_ctx(q, hctx, i) {
- hctx->sched_data = kmalloc_node(size, GFP_KERNEL, hctx->numa_node);
- if (!hctx->sched_data) {
- ret = -ENOMEM;
- goto error;
- }
-
- if (init) {
- ret = init(hctx);
- if (ret) {
- /*
- * We don't want to give exit() a partially
- * initialized sched_data. init() must clean up
- * if it fails.
- */
- kfree(hctx->sched_data);
- hctx->sched_data = NULL;
- goto error;
- }
- }
- }
-
- return 0;
-error:
- blk_mq_sched_free_hctx_data(q, exit);
- return ret;
-}
-EXPORT_SYMBOL_GPL(blk_mq_sched_init_hctx_data);
-
static void __blk_mq_sched_assign_ioc(struct request_queue *q,
struct request *rq,
struct bio *bio,
@@ -464,11 +427,24 @@ int blk_mq_sched_init_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
unsigned int hctx_idx)
{
struct elevator_queue *e = q->elevator;
+ int ret;
if (!e)
return 0;
- return blk_mq_sched_alloc_tags(q, hctx, hctx_idx);
+ ret = blk_mq_sched_alloc_tags(q, hctx, hctx_idx);
+ if (ret)
+ return ret;
+
+ if (e->type->ops.mq.init_hctx) {
+ ret = e->type->ops.mq.init_hctx(hctx, hctx_idx);
+ if (ret) {
+ blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx);
+ return ret;
+ }
+ }
+
+ return 0;
}
void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
@@ -479,12 +455,18 @@ void blk_mq_sched_exit_hctx(struct request_queue *q, struct blk_mq_hw_ctx *hctx,
if (!e)
return;
+ if (e->type->ops.mq.exit_hctx && hctx->sched_data) {
+ e->type->ops.mq.exit_hctx(hctx, hctx_idx);
+ hctx->sched_data = NULL;
+ }
+
blk_mq_sched_free_tags(q->tag_set, hctx, hctx_idx);
}
int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
{
struct blk_mq_hw_ctx *hctx;
+ struct elevator_queue *eq;
unsigned int i;
int ret;
@@ -509,6 +491,18 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
if (ret)
goto err;
+ if (e->ops.mq.init_hctx) {
+ queue_for_each_hw_ctx(q, hctx, i) {
+ ret = e->ops.mq.init_hctx(hctx, i);
+ if (ret) {
+ eq = q->elevator;
+ blk_mq_exit_sched(q, eq);
+ kobject_put(&eq->kobj);
+ return ret;
+ }
+ }
+ }
+
return 0;
err:
@@ -519,6 +513,17 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e)
{
+ struct blk_mq_hw_ctx *hctx;
+ unsigned int i;
+
+ if (e->type->ops.mq.exit_hctx) {
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (hctx->sched_data) {
+ e->type->ops.mq.exit_hctx(hctx, i);
+ hctx->sched_data = NULL;
+ }
+ }
+ }
if (e->type->ops.mq.exit_sched)
e->type->ops.mq.exit_sched(e);
blk_mq_sched_tags_teardown(q);
diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h
index e704956e0862..c6e760df0fb4 100644
--- a/block/blk-mq-sched.h
+++ b/block/blk-mq-sched.h
@@ -4,10 +4,6 @@
#include "blk-mq.h"
#include "blk-mq-tag.h"
-int blk_mq_sched_init_hctx_data(struct request_queue *q, size_t size,
- int (*init)(struct blk_mq_hw_ctx *),
- void (*exit)(struct blk_mq_hw_ctx *));
-
void blk_mq_sched_free_hctx_data(struct request_queue *q,
void (*exit)(struct blk_mq_hw_ctx *));
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index 22d39e8d4de1..b7ec315ee7e7 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -93,6 +93,8 @@ struct blk_mq_hw_ctx;
struct elevator_mq_ops {
int (*init_sched)(struct request_queue *, struct elevator_type *);
void (*exit_sched)(struct elevator_queue *);
+ int (*init_hctx)(struct blk_mq_hw_ctx *, unsigned int);
+ void (*exit_hctx)(struct blk_mq_hw_ctx *, unsigned int);
bool (*allow_merge)(struct request_queue *, struct request *, struct bio *);
bool (*bio_merge)(struct blk_mq_hw_ctx *, struct bio *);
--
2.12.2
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH 0/5] blk-mq: scheduler and hw queue initialization fixes/enhancements
2017-04-03 21:42 [PATCH 0/5] blk-mq: scheduler and hw queue initialization fixes/enhancements Omar Sandoval
` (4 preceding siblings ...)
2017-04-03 21:42 ` [PATCH 5/5] blk-mq-sched: provide hooks for initializing hardware queue data Omar Sandoval
@ 2017-04-04 17:09 ` Josef Bacik
5 siblings, 0 replies; 7+ messages in thread
From: Josef Bacik @ 2017-04-04 17:09 UTC (permalink / raw)
To: Omar Sandoval; +Cc: Jens Axboe, linux-block, kernel-team
> On Apr 3, 2017, at 5:42 PM, Omar Sandoval <osandov@osandov.com> wrote:
>
> From: Omar Sandoval <osandov@fb.com>
>
> Hi, Jens,
>
> This series has some fixes and enhancements for blk-mq:
>
> - Patch 1 is a cleanup in preparation for the rest of the series
> - Patch 2 is a fix necessary for patch 4 when scheduling is enabled,
> making sure we bring up new hardware queues with scheduler tags
> - Patch 3 makes error handling in elevator_switch() more robust, making
> us fall back to none like you recommended last time
> - Patch 4 is the remap fix from last week
> - Patch 5 is an extension of patch 2 for multiqueue schedulers that
> allocate per-hctx data. Nothing in-tree needs it, but Kyber will.
>
> Let me know if you'd prefer deferring this to 4.12 or want to apply 1-4
> for 4.11. These are based on block/for-next, so the latter might require
> a respin.
Tested with nbd, didn't crash, you can add
Tested-by: Josef Bacik <jbacik@fb.com>
Thanks,
Josef
^ permalink raw reply [flat|nested] 7+ messages in thread