lkml.org 
[lkml]   [2022]   [Feb]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[RFC V3 2/6] blk-wbt: make wbt pluggable
    Date
    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().

    Signed-off-by: Wang Jianchao (Kuaishou) <jianchao.wan9@gmail.com>
    ---
    block/blk-mq-debugfs.c | 2 --
    block/blk-rq-qos.h | 6 -----
    block/blk-wbt.c | 52 +++++++++++++++++++++++++++++++++++-------
    block/blk-wbt.h | 7 +++++-
    4 files changed, 50 insertions(+), 17 deletions(-)

    diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
    index 4da803bf5617..5094c2d3700a 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 586c3f5ec152..171a83d6de45 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,
    @@ -96,11 +95,6 @@ static inline struct rq_qos *rq_qos_by_id(struct request_queue *q, int id)
    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-wbt.c b/block/blk-wbt.c
    index 0c119be0e813..ad637fcf3919 100644
    --- a/block/blk-wbt.c
    +++ b/block/blk-wbt.c
    @@ -31,6 +31,13 @@
    #define CREATE_TRACE_POINTS
    #include <trace/events/wbt.h>

    +static struct rq_qos_ops wbt_rqos_ops;
    +
    +struct rq_qos *wbt_rq_qos(struct request_queue *q)
    +{
    + return rq_qos_by_id(q, wbt_rqos_ops.id);
    +}
    +
    static inline void wbt_clear_state(struct request *rq)
    {
    rq->wbt_flags = 0;
    @@ -628,9 +635,13 @@ 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);
    + struct rq_qos *rqos;
    +
    + spin_lock_irq(&q->queue_lock);
    + rqos = wbt_rq_qos(q);
    if (rqos)
    RQWB(rqos)->wc = write_cache_on;
    + spin_unlock_irq(&q->queue_lock);
    }

    /*
    @@ -638,14 +649,20 @@ void wbt_set_write_cache(struct request_queue *q, bool write_cache_on)
    */
    void wbt_enable_default(struct request_queue *q)
    {
    - struct rq_qos *rqos = wbt_rq_qos(q);
    + struct rq_qos *rqos;
    +
    + spin_lock_irq(&q->queue_lock);
    + rqos = wbt_rq_qos(q);

    /* Throttling already enabled? */
    if (rqos) {
    if (RQWB(rqos)->enable_state == WBT_STATE_OFF_DEFAULT)
    RQWB(rqos)->enable_state = WBT_STATE_ON_DEFAULT;
    +
    + spin_unlock_irq(&q->queue_lock);
    return;
    }
    + spin_unlock_irq(&q->queue_lock);

    /* Queue not registered? Maybe shutting down... */
    if (!blk_queue_registered(q))
    @@ -692,6 +709,7 @@ 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);
    @@ -702,15 +720,21 @@ static void wbt_exit(struct rq_qos *rqos)
    */
    void wbt_disable_default(struct request_queue *q)
    {
    - struct rq_qos *rqos = wbt_rq_qos(q);
    + struct rq_qos *rqos;
    struct rq_wb *rwb;
    +
    + spin_lock_irq(&q->queue_lock);
    + rqos = wbt_rq_qos(q);
    if (!rqos)
    - return;
    + goto out;
    +
    rwb = RQWB(rqos);
    if (rwb->enable_state == WBT_STATE_ON_DEFAULT) {
    blk_stat_deactivate(rwb->cb);
    rwb->enable_state = WBT_STATE_OFF_DEFAULT;
    }
    +out:
    + spin_unlock_irq(&q->queue_lock);
    }
    EXPORT_SYMBOL_GPL(wbt_disable_default);

    @@ -802,7 +826,9 @@ static const struct blk_mq_debugfs_attr wbt_debugfs_attrs[] = {
    };
    #endif

    +int wbt_init(struct request_queue *q);
    static struct rq_qos_ops wbt_rqos_ops = {
    + .name = "wbt",
    .throttle = wbt_wait,
    .issue = wbt_issue,
    .track = wbt_track,
    @@ -811,6 +837,7 @@ 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 +861,6 @@ 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 +870,7 @@ 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 +880,15 @@ 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..998e23f8bb57 100644
    --- a/block/blk-wbt.h
    +++ b/block/blk-wbt.h
    @@ -87,7 +87,7 @@ static inline unsigned int wbt_inflight(struct rq_wb *rwb)


    #ifdef CONFIG_BLK_WBT
    -
    +struct rq_qos *wbt_rq_qos(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 +101,11 @@ u64 wbt_default_latency_nsec(struct request_queue *);

    #else

    +static inline struct rq_qos *wbt_rq_qos(struct request_queue *q)
    +{
    + return NULL;
    +}
    +
    static inline void wbt_track(struct request *rq, enum wbt_flags flags)
    {
    }
    --
    2.17.1
    \
     
     \ /
      Last update: 2022-02-16 12:50    [W:2.750 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site