[Drbd-dev] [PATCH 04/16] block: use atomic bitops for ->queue_flags
Christoph Hellwig
hch at lst.de
Wed Nov 14 17:02:07 CET 2018
->queue_flags is generally not set or cleared in the fast path, and also
generally set or cleared one flag at a time. Make use of the normal
atomic bitops for it so that we don't need to take the queue_lock,
which is otherwise mostly unused in the core block layer now.
Signed-off-by: Christoph Hellwig <hch at lst.de>
---
block/blk-core.c | 54 ++++++----------------------------------
block/blk-mq.c | 2 +-
block/blk-settings.c | 10 +++-----
block/blk-sysfs.c | 28 +++++++++------------
block/blk.h | 56 ------------------------------------------
include/linux/blkdev.h | 1 -
6 files changed, 24 insertions(+), 127 deletions(-)
diff --git a/block/blk-core.c b/block/blk-core.c
index 1c9b6975cf0a..5c8e66a09d82 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -74,11 +74,7 @@ static struct workqueue_struct *kblockd_workqueue;
*/
void blk_queue_flag_set(unsigned int flag, struct request_queue *q)
{
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
- queue_flag_set(flag, q);
- spin_unlock_irqrestore(q->queue_lock, flags);
+ set_bit(flag, &q->queue_flags);
}
EXPORT_SYMBOL(blk_queue_flag_set);
@@ -89,11 +85,7 @@ EXPORT_SYMBOL(blk_queue_flag_set);
*/
void blk_queue_flag_clear(unsigned int flag, struct request_queue *q)
{
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
- queue_flag_clear(flag, q);
- spin_unlock_irqrestore(q->queue_lock, flags);
+ clear_bit(flag, &q->queue_flags);
}
EXPORT_SYMBOL(blk_queue_flag_clear);
@@ -107,38 +99,10 @@ EXPORT_SYMBOL(blk_queue_flag_clear);
*/
bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q)
{
- unsigned long flags;
- bool res;
-
- spin_lock_irqsave(q->queue_lock, flags);
- res = queue_flag_test_and_set(flag, q);
- spin_unlock_irqrestore(q->queue_lock, flags);
-
- return res;
+ return test_and_set_bit(flag, &q->queue_flags);
}
EXPORT_SYMBOL_GPL(blk_queue_flag_test_and_set);
-/**
- * blk_queue_flag_test_and_clear - atomically test and clear a queue flag
- * @flag: flag to be cleared
- * @q: request queue
- *
- * Returns the previous value of @flag - 0 if the flag was not set and 1 if
- * the flag was set.
- */
-bool blk_queue_flag_test_and_clear(unsigned int flag, struct request_queue *q)
-{
- unsigned long flags;
- bool res;
-
- spin_lock_irqsave(q->queue_lock, flags);
- res = queue_flag_test_and_clear(flag, q);
- spin_unlock_irqrestore(q->queue_lock, flags);
-
- return res;
-}
-EXPORT_SYMBOL_GPL(blk_queue_flag_test_and_clear);
-
void blk_rq_init(struct request_queue *q, struct request *rq)
{
memset(rq, 0, sizeof(*rq));
@@ -368,12 +332,10 @@ void blk_cleanup_queue(struct request_queue *q)
/* mark @q DYING, no new request or merges will be allowed afterwards */
mutex_lock(&q->sysfs_lock);
blk_set_queue_dying(q);
- spin_lock_irq(lock);
- queue_flag_set(QUEUE_FLAG_NOMERGES, q);
- queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
- queue_flag_set(QUEUE_FLAG_DYING, q);
- spin_unlock_irq(lock);
+ blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q);
+ blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
+ blk_queue_flag_set(QUEUE_FLAG_DYING, q);
mutex_unlock(&q->sysfs_lock);
/*
@@ -384,9 +346,7 @@ void blk_cleanup_queue(struct request_queue *q)
rq_qos_exit(q);
- spin_lock_irq(lock);
- queue_flag_set(QUEUE_FLAG_DEAD, q);
- spin_unlock_irq(lock);
+ blk_queue_flag_set(QUEUE_FLAG_DEAD, q);
/*
* make sure all in-progress dispatch are completed because
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 4c82b4b4fa3e..e2717e843727 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2756,7 +2756,7 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
if (!(set->flags & BLK_MQ_F_SG_MERGE))
- queue_flag_set_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
+ blk_queue_flag_set(QUEUE_FLAG_NO_SG_MERGE, q);
q->sg_reserved_size = INT_MAX;
diff --git a/block/blk-settings.c b/block/blk-settings.c
index cca83590a1dc..3abe831e92c8 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -834,16 +834,14 @@ EXPORT_SYMBOL(blk_set_queue_depth);
*/
void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
{
- spin_lock_irq(q->queue_lock);
if (wc)
- queue_flag_set(QUEUE_FLAG_WC, q);
+ blk_queue_flag_set(QUEUE_FLAG_WC, q);
else
- queue_flag_clear(QUEUE_FLAG_WC, q);
+ blk_queue_flag_clear(QUEUE_FLAG_WC, q);
if (fua)
- queue_flag_set(QUEUE_FLAG_FUA, q);
+ blk_queue_flag_set(QUEUE_FLAG_FUA, q);
else
- queue_flag_clear(QUEUE_FLAG_FUA, q);
- spin_unlock_irq(q->queue_lock);
+ blk_queue_flag_clear(QUEUE_FLAG_FUA, q);
wbt_set_write_cache(q, test_bit(QUEUE_FLAG_WC, &q->queue_flags));
}
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index d4b1b84ba8ca..22fd086eba9f 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -316,14 +316,12 @@ static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
if (ret < 0)
return ret;
- spin_lock_irq(q->queue_lock);
- queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
- queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
+ blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
+ blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
if (nm == 2)
- queue_flag_set(QUEUE_FLAG_NOMERGES, q);
+ blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q);
else if (nm)
- queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
- spin_unlock_irq(q->queue_lock);
+ blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
return ret;
}
@@ -347,18 +345,16 @@ queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
if (ret < 0)
return ret;
- spin_lock_irq(q->queue_lock);
if (val == 2) {
- queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
- queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
+ blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
+ blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
} else if (val == 1) {
- queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
- queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
+ blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
+ blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
} else if (val == 0) {
- queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
- queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
+ blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
+ blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
}
- spin_unlock_irq(q->queue_lock);
#endif
return ret;
}
@@ -889,7 +885,7 @@ int blk_register_queue(struct gendisk *disk)
WARN_ONCE(test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags),
"%s is registering an already registered queue\n",
kobject_name(&dev->kobj));
- queue_flag_set_unlocked(QUEUE_FLAG_REGISTERED, q);
+ blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
/*
* SCSI probing may synchronously create and destroy a lot of
@@ -901,7 +897,7 @@ int blk_register_queue(struct gendisk *disk)
* request_queues for non-existent devices never get registered.
*/
if (!blk_queue_init_done(q)) {
- queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
+ blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q);
percpu_ref_switch_to_percpu(&q->q_usage_counter);
}
diff --git a/block/blk.h b/block/blk.h
index 08a5845b03ba..f2ddc71e93da 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -48,62 +48,6 @@ static inline void queue_lockdep_assert_held(struct request_queue *q)
lockdep_assert_held(q->queue_lock);
}
-static inline void queue_flag_set_unlocked(unsigned int flag,
- struct request_queue *q)
-{
- if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
- kref_read(&q->kobj.kref))
- lockdep_assert_held(q->queue_lock);
- __set_bit(flag, &q->queue_flags);
-}
-
-static inline void queue_flag_clear_unlocked(unsigned int flag,
- struct request_queue *q)
-{
- if (test_bit(QUEUE_FLAG_INIT_DONE, &q->queue_flags) &&
- kref_read(&q->kobj.kref))
- lockdep_assert_held(q->queue_lock);
- __clear_bit(flag, &q->queue_flags);
-}
-
-static inline int queue_flag_test_and_clear(unsigned int flag,
- struct request_queue *q)
-{
- queue_lockdep_assert_held(q);
-
- if (test_bit(flag, &q->queue_flags)) {
- __clear_bit(flag, &q->queue_flags);
- return 1;
- }
-
- return 0;
-}
-
-static inline int queue_flag_test_and_set(unsigned int flag,
- struct request_queue *q)
-{
- queue_lockdep_assert_held(q);
-
- if (!test_bit(flag, &q->queue_flags)) {
- __set_bit(flag, &q->queue_flags);
- return 0;
- }
-
- return 1;
-}
-
-static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
-{
- queue_lockdep_assert_held(q);
- __set_bit(flag, &q->queue_flags);
-}
-
-static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
-{
- queue_lockdep_assert_held(q);
- __clear_bit(flag, &q->queue_flags);
-}
-
static inline struct blk_flush_queue *
blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)
{
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1aa94759d219..2b887e24837e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -624,7 +624,6 @@ struct request_queue {
void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
-bool blk_queue_flag_test_and_clear(unsigned int flag, struct request_queue *q);
#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
#define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
--
2.19.1
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