From: Wang Jianchao <wangjianchao@xxxxxxxxxxxx>
Make blk-iolatency pluggable and modular. Then we can close or open
it through /sys/block/xxx/queue/qos and rmmod the module if we don't
need it which can release one blkcg policy slot.
Signed-off-by: Wang Jianchao <wangjianchao@xxxxxxxxxxxx>
---
block/Kconfig | 2 +-
block/Makefile | 4 +++-
block/blk-cgroup.c | 6 ------
block/blk-iolatency.c | 39 +++++++++++++++++++++++++++++++--------
block/blk-mq-debugfs.c | 2 --
block/blk-rq-qos.h | 6 ------
block/blk.h | 6 ------
7 files changed, 35 insertions(+), 30 deletions(-)
diff --git a/block/Kconfig b/block/Kconfig
index c6ce41a5e5b2..1c0d05df2aec 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -111,7 +111,7 @@ config BLK_WBT_MQ
Enable writeback throttling by default for request-based block devices.
config BLK_CGROUP_IOLATENCY
- bool "Enable support for latency based cgroup IO protection"
+ tristate "Enable support for latency based cgroup IO protection"
depends on BLK_CGROUP
help
Enabling this option enables the .latency interface for IO throttling.
diff --git a/block/Makefile b/block/Makefile
index 44df57e562bf..ccf61c57e1d4 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -18,7 +18,9 @@ obj-$(CONFIG_BLK_CGROUP) += blk-cgroup.o
obj-$(CONFIG_BLK_CGROUP_RWSTAT) += blk-cgroup-rwstat.o
obj-$(CONFIG_BLK_DEV_THROTTLING) += blk-throttle.o
obj-$(CONFIG_BLK_CGROUP_IOPRIO) += blk-ioprio.o
-obj-$(CONFIG_BLK_CGROUP_IOLATENCY) += blk-iolatency.o
+iolat-y := blk-iolatency.o
+obj-$(CONFIG_BLK_CGROUP_IOLATENCY) += iolat.o
+
obj-$(CONFIG_BLK_CGROUP_IOCOST) += blk-iocost.o
obj-$(CONFIG_MQ_IOSCHED_DEADLINE) += mq-deadline.o
obj-$(CONFIG_MQ_IOSCHED_KYBER) += kyber-iosched.o
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index fb56d74f1c8e..fd874dfd38ed 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1212,12 +1212,6 @@ int blkcg_init_queue(struct request_queue *q)
if (ret)
goto err_destroy_all;
- ret = blk_iolatency_init(q);
- if (ret) {
- blk_throtl_exit(q);
- goto err_destroy_all;
- }
-
return 0;
err_destroy_all:
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index 6593c7123b97..6aaf0775e484 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -90,6 +90,12 @@ struct blk_iolatency {
atomic_t enabled;
};
+static struct rq_qos_ops blkcg_iolatency_ops;
+static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
+{
+ return rq_qos_by_id(q, blkcg_iolatency_ops.id);
+}
+
static inline struct blk_iolatency *BLKIOLATENCY(struct rq_qos *rqos)
{
return container_of(rqos, struct blk_iolatency, rqos);
@@ -646,13 +652,21 @@ static void blkcg_iolatency_exit(struct rq_qos *rqos)
del_timer_sync(&blkiolat->timer);
blkcg_deactivate_policy(rqos->q, &blkcg_policy_iolatency);
+ rq_qos_deactivate(rqos);
kfree(blkiolat);
}
+static int blk_iolatency_init(struct request_queue *q);
static struct rq_qos_ops blkcg_iolatency_ops = {
+#if IS_MODULE(CONFIG_BLK_CGROUP_IOLATENCY)
+ .owner = THIS_MODULE,
+#endif
+ .name = "iolat",
+ .flags = RQOS_FLAG_CGRP_POL,
.throttle = blkcg_iolatency_throttle,
.done_bio = blkcg_iolatency_done_bio,
.exit = blkcg_iolatency_exit,
+ .init = blk_iolatency_init,
};
static void blkiolatency_timer_fn(struct timer_list *t)
@@ -727,15 +741,10 @@ int blk_iolatency_init(struct request_queue *q)
return -ENOMEM;
rqos = &blkiolat->rqos;
- rqos->id = RQ_QOS_LATENCY;
- rqos->ops = &blkcg_iolatency_ops;
- rqos->q = q;
-
- rq_qos_add(q, rqos);
-
+ rq_qos_activate(q, rqos, &blkcg_iolatency_ops);
ret = blkcg_activate_policy(q, &blkcg_policy_iolatency);
if (ret) {
- rq_qos_del(q, rqos);
+ rq_qos_deactivate(rqos);
kfree(blkiolat);
return ret;
}
@@ -1046,13 +1055,27 @@ static struct blkcg_policy blkcg_policy_iolatency = {
static int __init iolatency_init(void)
{
- return blkcg_policy_register(&blkcg_policy_iolatency);
+ int ret;
+
+ ret = rq_qos_register(&blkcg_iolatency_ops);
+ if (ret)
+ return ret;
+
+ ret = blkcg_policy_register(&blkcg_policy_iolatency);
+ if (ret)
+ rq_qos_unregister(&blkcg_iolatency_ops);
+
+ return ret;
}
static void __exit iolatency_exit(void)
{
blkcg_policy_unregister(&blkcg_policy_iolatency);
+ rq_qos_unregister(&blkcg_iolatency_ops);
}
module_init(iolatency_init);
module_exit(iolatency_exit);
+MODULE_AUTHOR("Josef Bacik");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Latency based cgroup IO protection");
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 9c786b63c847..57c33f4730f2 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -820,8 +820,6 @@ void blk_mq_debugfs_unregister_sched(struct request_queue *q)
static const char *rq_qos_id_to_name(enum rq_qos_id id)
{
switch (id) {
- case RQ_QOS_LATENCY:
- return "latency";
case RQ_QOS_COST:
return "cost";
case RQ_QOS_IOPRIO:
diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h
index de82eb951bdd..6ca46c69e325 100644
--- a/block/blk-rq-qos.h
+++ b/block/blk-rq-qos.h
@@ -14,7 +14,6 @@
struct blk_mq_debugfs_attr;
enum rq_qos_id {
- RQ_QOS_LATENCY,
RQ_QOS_COST,
RQ_QOS_IOPRIO,
};
@@ -85,11 +84,6 @@ static inline struct rq_qos *rq_qos_by_id(struct request_queue *q, int id)
return rqos;
}
-static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
-{
- return rq_qos_by_id(q, RQ_QOS_LATENCY);
-}
-
static inline void rq_wait_init(struct rq_wait *rq_wait)
{
atomic_set(&rq_wait->inflight, 0);
diff --git a/block/blk.h b/block/blk.h
index ccde6e6f1736..e2e4fbb9a58d 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -436,12 +436,6 @@ static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
__blk_queue_bounce(q, bio);
}
-#ifdef CONFIG_BLK_CGROUP_IOLATENCY
-extern int blk_iolatency_init(struct request_queue *q);
-#else
-static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
-#endif
-
struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);
#ifdef CONFIG_BLK_DEV_ZONED
--
2.17.1
