Commit a33801e8b473 ("block, bfq: move debug blkio stats behind
CONFIG_DEBUG_BLK_CGROUP") introduced two batches of confusing ifdefs:
one reported in [1], plus a similar one in another function. This
commit removes both batches, in the way suggested in [1].[1] https://www.spinics.net/lists/linux-block/msg20043.html Fixes: a33801e8b473 ("block, bfq: move debug blkio stats behind CONFIG_DEBUG_BLK_CGROUP") Reported-by: Linus Torvalds <torva...@linux-foundation.org> Tested-by: Luca Miccio <lucmic...@gmail.com> Signed-off-by: Paolo Valente <paolo.vale...@linaro.org> --- block/bfq-iosched.c | 127 +++++++++++++++++++++++++++++----------------------- 1 file changed, 72 insertions(+), 55 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index bcb6d21..0153fea 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -3689,35 +3689,16 @@ static struct request *__bfq_dispatch_request(struct blk_mq_hw_ctx *hctx) return rq; } -static struct request *bfq_dispatch_request(struct blk_mq_hw_ctx *hctx) -{ - struct bfq_data *bfqd = hctx->queue->elevator->elevator_data; - struct request *rq; -#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP) - struct bfq_queue *in_serv_queue, *bfqq; - bool waiting_rq, idle_timer_disabled; -#endif - - spin_lock_irq(&bfqd->lock); - #if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP) - in_serv_queue = bfqd->in_service_queue; - waiting_rq = in_serv_queue && bfq_bfqq_wait_request(in_serv_queue); - - rq = __bfq_dispatch_request(hctx); - - idle_timer_disabled = - waiting_rq && !bfq_bfqq_wait_request(in_serv_queue); - -#else - rq = __bfq_dispatch_request(hctx); -#endif - spin_unlock_irq(&bfqd->lock); +static inline void bfq_update_dispatch_stats(struct request *rq, + spinlock_t *queue_lock, + struct bfq_queue *in_serv_queue, + bool idle_timer_disabled) +{ + struct bfq_queue *bfqq = rq ? RQ_BFQQ(rq) : NULL; -#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP) - bfqq = rq ? RQ_BFQQ(rq) : NULL; if (!idle_timer_disabled && !bfqq) - return rq; + return; /* * rq and bfqq are guaranteed to exist until this function @@ -3732,7 +3713,7 @@ static struct request *bfq_dispatch_request(struct blk_mq_hw_ctx *hctx) * In addition, the following queue lock guarantees that * bfqq_group(bfqq) exists as well. */ - spin_lock_irq(hctx->queue->queue_lock); + spin_lock_irq(queue_lock); if (idle_timer_disabled) /* * Since the idle timer has been disabled, @@ -3751,9 +3732,37 @@ static struct request *bfq_dispatch_request(struct blk_mq_hw_ctx *hctx) bfqg_stats_set_start_empty_time(bfqg); bfqg_stats_update_io_remove(bfqg, rq->cmd_flags); } - spin_unlock_irq(hctx->queue->queue_lock); + spin_unlock_irq(queue_lock); +} +#else +static inline void bfq_update_dispatch_stats(struct request *rq, + spinlock_t *queue_lock, + struct bfq_queue *in_serv_queue, + bool idle_timer_disabled) {} #endif +static struct request *bfq_dispatch_request(struct blk_mq_hw_ctx *hctx) +{ + struct bfq_data *bfqd = hctx->queue->elevator->elevator_data; + struct request *rq; + struct bfq_queue *in_serv_queue; + bool waiting_rq, idle_timer_disabled; + + spin_lock_irq(&bfqd->lock); + + in_serv_queue = bfqd->in_service_queue; + waiting_rq = in_serv_queue && bfq_bfqq_wait_request(in_serv_queue); + + rq = __bfq_dispatch_request(hctx); + + idle_timer_disabled = + waiting_rq && !bfq_bfqq_wait_request(in_serv_queue); + + spin_unlock_irq(&bfqd->lock); + + bfq_update_dispatch_stats(rq, hctx->queue->queue_lock, in_serv_queue, + idle_timer_disabled); + return rq; } @@ -4276,16 +4285,46 @@ static bool __bfq_insert_request(struct bfq_data *bfqd, struct request *rq) return idle_timer_disabled; } +#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP) +static inline void bfq_update_insert_stats(struct bfq_queue *bfqq, + spinlock_t *queue_lock, + bool idle_timer_disabled, + unsigned int cmd_flags) +{ + if (!bfqq) + return; + + /* + * bfqq still exists, because it can disappear only after + * either it is merged with another queue, or the process it + * is associated with exits. But both actions must be taken by + * the same process currently executing this flow of + * instructions. + * + * In addition, the following queue lock guarantees that + * bfqq_group(bfqq) exists as well. + */ + spin_lock_irq(queue_lock); + bfqg_stats_update_io_add(bfqq_group(bfqq), bfqq, cmd_flags); + if (idle_timer_disabled) + bfqg_stats_update_idle_time(bfqq_group(bfqq)); + spin_unlock_irq(queue_lock); +} +#else +static inline void bfq_update_insert_stats(struct bfq_queue *bfqq, + spinlock_t *queue_lock, + bool idle_timer_disabled, + unsigned int cmd_flags) {} +#endif + static void bfq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, bool at_head) { struct request_queue *q = hctx->queue; struct bfq_data *bfqd = q->elevator->elevator_data; -#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP) struct bfq_queue *bfqq = RQ_BFQQ(rq); bool idle_timer_disabled = false; unsigned int cmd_flags; -#endif spin_lock_irq(&bfqd->lock); if (blk_mq_sched_try_insert_merge(q, rq)) { @@ -4304,7 +4343,6 @@ static void bfq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, else list_add_tail(&rq->queuelist, &bfqd->dispatch); } else { -#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP) idle_timer_disabled = __bfq_insert_request(bfqd, rq); /* * Update bfqq, because, if a queue merge has occurred @@ -4312,9 +4350,6 @@ static void bfq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, * redirected into a new queue. */ bfqq = RQ_BFQQ(rq); -#else - __bfq_insert_request(bfqd, rq); -#endif if (rq_mergeable(rq)) { elv_rqhash_add(q, rq); @@ -4323,35 +4358,17 @@ static void bfq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, } } -#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP) /* * Cache cmd_flags before releasing scheduler lock, because rq * may disappear afterwards (for example, because of a request * merge). */ cmd_flags = rq->cmd_flags; -#endif + spin_unlock_irq(&bfqd->lock); -#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP) - if (!bfqq) - return; - /* - * bfqq still exists, because it can disappear only after - * either it is merged with another queue, or the process it - * is associated with exits. But both actions must be taken by - * the same process currently executing this flow of - * instruction. - * - * In addition, the following queue lock guarantees that - * bfqq_group(bfqq) exists as well. - */ - spin_lock_irq(q->queue_lock); - bfqg_stats_update_io_add(bfqq_group(bfqq), bfqq, cmd_flags); - if (idle_timer_disabled) - bfqg_stats_update_idle_time(bfqq_group(bfqq)); - spin_unlock_irq(q->queue_lock); -#endif + bfq_update_insert_stats(bfqq, q->queue_lock, idle_timer_disabled, + cmd_flags); } static void bfq_insert_requests(struct blk_mq_hw_ctx *hctx, -- 2.10.0
