This patch makes wbt pluggable through /sys/block/xxx/queue/qos.
Some queue_lock/unlock is added to protect rq_qos_by_id() in
wbt_rq_qos(). By default, wbt is enabled which is same with previous
code.
Signed-off-by: Wang Jianchao (Kuaishou) <jianchao.wan9@xxxxxxxxx>
---
block/blk-mq-debugfs.c | 2 --
block/blk-rq-qos.h | 6 -----
block/blk-sysfs.c | 6 ++---
block/blk-wbt.c | 56 +++++++++++++++++++++++++++++++++++++-----
block/blk-wbt.h | 6 +++++
5 files changed, 58 insertions(+), 18 deletions(-)
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 24d47bc90b4a..073ca7fca9b3 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -826,8 +826,6 @@ 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_WBT:
- return "wbt";
case RQ_QOS_LATENCY:
return "latency";
case RQ_QOS_COST:
diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h
index aa6ef12637a0..8ce3f48b16b9 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_WBT,
RQ_QOS_LATENCY,
RQ_QOS_COST,
RQ_QOS_IOPRIO,
@@ -76,11 +75,6 @@ static inline struct rq_qos *rq_qos_id(struct request_queue *q,
return rqos;
}
-static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
-{
- return rq_qos_id(q, RQ_QOS_WBT);
-}
-
static inline struct rq_qos *blkcg_rq_qos(struct request_queue *q)
{
return rq_qos_id(q, RQ_QOS_LATENCY);
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 9f32882ceb2f..c713d6b305cc 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -463,7 +463,7 @@ static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page,
static ssize_t queue_wb_lat_show(struct request_queue *q, char *page)
{
- if (!wbt_rq_qos(q))
+ if (!wbt_opened(q))
return -EINVAL;
return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000));
@@ -472,7 +472,6 @@ static ssize_t queue_wb_lat_show(struct request_queue *q, char *page)
static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
size_t count)
{
- struct rq_qos *rqos;
ssize_t ret;
s64 val;
@@ -482,8 +481,7 @@ static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
if (val < -1)
return -EINVAL;
- rqos = wbt_rq_qos(q);
- if (!rqos) {
+ if (!wbt_opened(q)) {
ret = wbt_init(q);
if (ret)
return ret;
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 0c119be0e813..44a920d83475 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -31,6 +31,22 @@
#define CREATE_TRACE_POINTS
#include <trace/events/wbt.h>
+static struct rq_qos_ops wbt_rqos_ops;
+
+static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
+{
+ return rq_qos_get(q, wbt_rqos_ops.id);
+}
+
+bool wbt_opened(struct request_queue *q)
+{
+ struct rq_qos *rqos = wbt_rq_qos(q);
+
+ rq_qos_put(rqos);
+
+ return !!rqos;
+}
+
static inline void wbt_clear_state(struct request *rq)
{
rq->wbt_flags = 0;
@@ -425,19 +441,27 @@ static void wbt_update_limits(struct rq_wb *rwb)
u64 wbt_get_min_lat(struct request_queue *q)
{
struct rq_qos *rqos = wbt_rq_qos(q);
+ u64 nsec;
+
if (!rqos)
return 0;
- return RQWB(rqos)->min_lat_nsec;
+
+ nsec = RQWB(rqos)->min_lat_nsec;
+ rq_qos_put(rqos);
+
+ return nsec;
}
void wbt_set_min_lat(struct request_queue *q, u64 val)
{
struct rq_qos *rqos = wbt_rq_qos(q);
+
if (!rqos)
return;
RQWB(rqos)->min_lat_nsec = val;
RQWB(rqos)->enable_state = WBT_STATE_ON_MANUAL;
wbt_update_limits(RQWB(rqos));
+ rq_qos_put(rqos);
}
@@ -629,8 +653,11 @@ static void wbt_requeue(struct rq_qos *rqos, struct request *rq)
void wbt_set_write_cache(struct request_queue *q, bool write_cache_on)
{
struct rq_qos *rqos = wbt_rq_qos(q);
- if (rqos)
+
+ if (rqos) {
RQWB(rqos)->wc = write_cache_on;
+ rq_qos_put(rqos);
+ }
}
/*
@@ -644,6 +671,8 @@ void wbt_enable_default(struct request_queue *q)
if (rqos) {
if (RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT)
RQWB(rqos)->enable_state = WBT_STATE_ON_DEFAULT;
+
+ rq_qos_put(rqos);
return;
}
@@ -692,6 +721,7 @@ static void wbt_exit(struct rq_qos *rqos)
struct rq_wb *rwb = RQWB(rqos);
struct request_queue *q = rqos->q;
+ rq_qos_deactivate(rqos);
blk_stat_remove_callback(q, rwb->cb);
blk_stat_free_callback(rwb->cb);
kfree(rwb);
@@ -704,13 +734,16 @@ void wbt_disable_default(struct request_queue *q)
{
struct rq_qos *rqos = wbt_rq_qos(q);
struct rq_wb *rwb;
+
if (!rqos)
return;
+
rwb = RQWB(rqos);
if (rwb->enable_state == WBT_STATE_ON_DEFAULT) {
blk_stat_deactivate(rwb->cb);
rwb->enable_state = WBT_STATE_OFF_DEFAULT;
}
+ rq_qos_put(rqos);
}
EXPORT_SYMBOL_GPL(wbt_disable_default);
@@ -803,6 +836,7 @@ static const struct blk_mq_debugfs_attr wbt_debugfs_attrs[] = {
#endif
static struct rq_qos_ops wbt_rqos_ops = {
+ .name = "wbt",
.throttle = wbt_wait,
.issue = wbt_issue,
.track = wbt_track,
@@ -811,6 +845,7 @@ static struct rq_qos_ops wbt_rqos_ops = {
.cleanup = wbt_cleanup,
.queue_depth_changed = wbt_queue_depth_changed,
.exit = wbt_exit,
+ .init = wbt_init,
#ifdef CONFIG_BLK_DEBUG_FS
.debugfs_attrs = wbt_debugfs_attrs,
#endif
@@ -834,9 +869,6 @@ int wbt_init(struct request_queue *q)
for (i = 0; i < WBT_NUM_RWQ; i++)
rq_wait_init(&rwb->rq_wait[i]);
- rwb->rqos.id = RQ_QOS_WBT;
- rwb->rqos.ops = &wbt_rqos_ops;
- rwb->rqos.q = q;
rwb->last_comp = rwb->last_issue = jiffies;
rwb->win_nsec = RWB_WINDOW_NSEC;
rwb->enable_state = WBT_STATE_ON_DEFAULT;
@@ -846,7 +878,7 @@ int wbt_init(struct request_queue *q)
/*
* Assign rwb and add the stats callback.
*/
- rq_qos_add(q, &rwb->rqos);
+ rq_qos_activate(q, &rwb->rqos, &wbt_rqos_ops);
blk_stat_add_callback(q, rwb->cb);
rwb->min_lat_nsec = wbt_default_latency_nsec(q);
@@ -856,3 +888,15 @@ int wbt_init(struct request_queue *q)
return 0;
}
+
+static __init int wbt_mod_init(void)
+{
+ return rq_qos_register(&wbt_rqos_ops);
+}
+
+static __exit void wbt_mod_exit(void)
+{
+ return rq_qos_unregister(&wbt_rqos_ops);
+}
+module_init(wbt_mod_init);
+module_exit(wbt_mod_exit);
diff --git a/block/blk-wbt.h b/block/blk-wbt.h
index 2eb01becde8c..f128dcf662db 100644
--- a/block/blk-wbt.h
+++ b/block/blk-wbt.h
@@ -88,6 +88,7 @@ static inline unsigned int wbt_inflight(struct rq_wb *rwb)
#ifdef CONFIG_BLK_WBT
+bool wbt_opened(struct request_queue *q);
int wbt_init(struct request_queue *);
void wbt_disable_default(struct request_queue *);
void wbt_enable_default(struct request_queue *);
@@ -101,6 +102,11 @@ u64 wbt_default_latency_nsec(struct request_queue *);
#else
+bool wbt_opened(struct request_queue *q)
+{
+ return false;
+}
+
static inline void wbt_track(struct request *rq, enum wbt_flags flags)
{
}
--
2.17.1
