[09/14] block/mq-deadline: Improve compile-time argument checking

Message ID	20210608230703.19510-10-bvanassche@acm.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-block-owner@kernel.org> From: Bart Van Assche <bvanassche@acm.org> To: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org, Christoph Hellwig <hch@lst.de>, Jaegeuk Kim <jaegeuk@kernel.org>, Bart Van Assche <bvanassche@acm.org>, Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>, Hannes Reinecke <hare@suse.de>, Johannes Thumshirn <johannes.thumshirn@wdc.com>, Himanshu Madhani <himanshu.madhani@oracle.com>, Damien Le Moal <damien.lemoal@wdc.com>, Ming Lei <ming.lei@redhat.com> Subject: [PATCH 09/14] block/mq-deadline: Improve compile-time argument checking Date: Tue, 8 Jun 2021 16:06:58 -0700 Message-Id: <20210608230703.19510-10-bvanassche@acm.org> In-Reply-To: <20210608230703.19510-1-bvanassche@acm.org> References: <20210608230703.19510-1-bvanassche@acm.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	Improve I/O priority support \| expand [00/14] Improve I/O priority support [01/14] block/Kconfig: Make the BLK_WBT and BLK_WBT_MQ entries consecutive [02/14] block/blk-cgroup: Swap the blk_throtl_init() and blk_iolatency_init() calls [03/14] block/blk-rq-qos: Move a function from a header file into a C file [04/14] block: Introduce the ioprio rq-qos policy [05/14] block/mq-deadline: Add several comments [06/14] block/mq-deadline: Add two lockdep_assert_held() statements [07/14] block/mq-deadline: Remove two local variables [08/14] block/mq-deadline: Rename dd_init_queue() and dd_exit_queue() [09/14] block/mq-deadline: Improve compile-time argument checking [10/14] block/mq-deadline: Improve the sysfs show and store macros [11/14] block/mq-deadline: Reserve 25% of scheduler tags for synchronous requests [12/14] block/mq-deadline: Add I/O priority support [13/14] block/mq-deadline: Add cgroup support [14/14] block/mq-deadline: Prioritize high-priority requests

diff --git a/block/mq-deadline.c b/block/mq-deadline.c index d823ba7cb084..69126beff77d 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -35,6 +35,13 @@ static const int writes_starved = 2; /* max times reads can starve a write */ static const int fifo_batch = 16; /* # of sequential requests treated as one by the above parameters. For throughput. */ +enum dd_data_dir { + DD_READ = READ, + DD_WRITE = WRITE, +}; + +enum { DD_DIR_COUNT = 2 }; + struct deadline_data { /* * run time data @@ -43,20 +50,20 @@ struct deadline_data { /* * requests (deadline_rq s) are present on both sort_list and fifo_list */ - struct rb_root sort_list[2]; - struct list_head fifo_list[2]; + struct rb_root sort_list[DD_DIR_COUNT]; + struct list_head fifo_list[DD_DIR_COUNT]; /* * next in sort order. read, write or both are NULL */ - struct request *next_rq[2]; + struct request *next_rq[DD_DIR_COUNT]; unsigned int batching; /* number of sequential requests made */ unsigned int starved; /* times reads have starved writes */ /* * settings that change how the i/o scheduler behaves */ - int fifo_expire[2]; + int fifo_expire[DD_DIR_COUNT]; int fifo_batch; int writes_starved; int front_merges; @@ -97,7 +104,7 @@ deadline_add_rq_rb(struct deadline_data *dd, struct request *rq) static inline void deadline_del_rq_rb(struct deadline_data *dd, struct request *rq) { - const int data_dir = rq_data_dir(rq); + const enum dd_data_dir data_dir = rq_data_dir(rq); if (dd->next_rq[data_dir] == rq) dd->next_rq[data_dir] = deadline_latter_request(rq); @@ -169,10 +176,10 @@ static void dd_merged_requests(struct request_queue *q, struct request *req, static void deadline_move_request(struct deadline_data *dd, struct request *rq) { - const int data_dir = rq_data_dir(rq); + const enum dd_data_dir data_dir = rq_data_dir(rq); - dd->next_rq[READ] = NULL; - dd->next_rq[WRITE] = NULL; + dd->next_rq[DD_READ] = NULL; + dd->next_rq[DD_WRITE] = NULL; dd->next_rq[data_dir] = deadline_latter_request(rq); /* @@ -185,9 +192,10 @@ deadline_move_request(struct deadline_data *dd, struct request *rq) * deadline_check_fifo returns 0 if there are no expired requests on the fifo, * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir]) */ -static inline int deadline_check_fifo(struct deadline_data *dd, int ddir) +static inline int deadline_check_fifo(struct deadline_data *dd, + enum dd_data_dir data_dir) { - struct request *rq = rq_entry_fifo(dd->fifo_list[ddir].next); + struct request *rq = rq_entry_fifo(dd->fifo_list[data_dir].next); /* * rq is expired! @@ -203,19 +211,16 @@ static inline int deadline_check_fifo(struct deadline_data *dd, int ddir) * dispatch using arrival ordered lists. */ static struct request * -deadline_fifo_request(struct deadline_data *dd, int data_dir) +deadline_fifo_request(struct deadline_data *dd, enum dd_data_dir data_dir) { struct request *rq; unsigned long flags; - if (WARN_ON_ONCE(data_dir != READ && data_dir != WRITE)) - return NULL; - if (list_empty(&dd->fifo_list[data_dir])) return NULL; rq = rq_entry_fifo(dd->fifo_list[data_dir].next); - if (data_dir == READ || !blk_queue_is_zoned(rq->q)) + if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q)) return rq; /* @@ -223,7 +228,7 @@ deadline_fifo_request(struct deadline_data *dd, int data_dir) * an unlocked target zone. */ spin_lock_irqsave(&dd->zone_lock, flags); - list_for_each_entry(rq, &dd->fifo_list[WRITE], queuelist) { + list_for_each_entry(rq, &dd->fifo_list[DD_WRITE], queuelist) { if (blk_req_can_dispatch_to_zone(rq)) goto out; } @@ -239,19 +244,16 @@ deadline_fifo_request(struct deadline_data *dd, int data_dir) * dispatch using sector position sorted lists. */ static struct request * -deadline_next_request(struct deadline_data *dd, int data_dir) +deadline_next_request(struct deadline_data *dd, enum dd_data_dir data_dir) { struct request *rq; unsigned long flags; - if (WARN_ON_ONCE(data_dir != READ && data_dir != WRITE)) - return NULL; - rq = dd->next_rq[data_dir]; if (!rq) return NULL; - if (data_dir == READ || !blk_queue_is_zoned(rq->q)) + if (data_dir == DD_READ || !blk_queue_is_zoned(rq->q)) return rq; /* @@ -276,7 +278,7 @@ deadline_next_request(struct deadline_data *dd, int data_dir) static struct request *__dd_dispatch_request(struct deadline_data *dd) { struct request *rq, *next_rq; - int data_dir; + enum dd_data_dir data_dir; lockdep_assert_held(&dd->lock); @@ -289,9 +291,9 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd) /* * batches are currently reads XOR writes */ - rq = deadline_next_request(dd, WRITE); + rq = deadline_next_request(dd, DD_WRITE); if (!rq) - rq = deadline_next_request(dd, READ); + rq = deadline_next_request(dd, DD_READ); if (rq && dd->batching < dd->fifo_batch) /* we have a next request are still entitled to batch */ @@ -302,14 +304,14 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd) * data direction (read / write) */ - if (!list_empty(&dd->fifo_list[READ])) { - BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[READ])); + if (!list_empty(&dd->fifo_list[DD_READ])) { + BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[DD_READ])); - if (deadline_fifo_request(dd, WRITE) && + if (deadline_fifo_request(dd, DD_WRITE) && (dd->starved++ >= dd->writes_starved)) goto dispatch_writes; - data_dir = READ; + data_dir = DD_READ; goto dispatch_find_request; } @@ -318,13 +320,13 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd) * there are either no reads or writes have been starved */ - if (!list_empty(&dd->fifo_list[WRITE])) { + if (!list_empty(&dd->fifo_list[DD_WRITE])) { dispatch_writes: - BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[WRITE])); + BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[DD_WRITE])); dd->starved = 0; - data_dir = WRITE; + data_dir = DD_WRITE; goto dispatch_find_request; } @@ -399,8 +401,8 @@ static void dd_exit_sched(struct elevator_queue *e) { struct deadline_data *dd = e->elevator_data; - BUG_ON(!list_empty(&dd->fifo_list[READ])); - BUG_ON(!list_empty(&dd->fifo_list[WRITE])); + BUG_ON(!list_empty(&dd->fifo_list[DD_READ])); + BUG_ON(!list_empty(&dd->fifo_list[DD_WRITE])); kfree(dd); } @@ -424,12 +426,12 @@ static int dd_init_sched(struct request_queue *q, struct elevator_type *e) } eq->elevator_data = dd; - INIT_LIST_HEAD(&dd->fifo_list[READ]); - INIT_LIST_HEAD(&dd->fifo_list[WRITE]); - dd->sort_list[READ] = RB_ROOT; - dd->sort_list[WRITE] = RB_ROOT; - dd->fifo_expire[READ] = read_expire; - dd->fifo_expire[WRITE] = write_expire; + INIT_LIST_HEAD(&dd->fifo_list[DD_READ]); + INIT_LIST_HEAD(&dd->fifo_list[DD_WRITE]); + dd->sort_list[DD_READ] = RB_ROOT; + dd->sort_list[DD_WRITE] = RB_ROOT; + dd->fifo_expire[DD_READ] = read_expire; + dd->fifo_expire[DD_WRITE] = write_expire; dd->writes_starved = writes_starved; dd->front_merges = 1; dd->fifo_batch = fifo_batch; @@ -497,7 +499,7 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq, { struct request_queue *q = hctx->queue; struct deadline_data *dd = q->elevator->elevator_data; - const int data_dir = rq_data_dir(rq); + const enum dd_data_dir data_dir = rq_data_dir(rq); lockdep_assert_held(&dd->lock); @@ -585,7 +587,7 @@ static void dd_finish_request(struct request *rq) spin_lock_irqsave(&dd->zone_lock, flags); blk_req_zone_write_unlock(rq); - if (!list_empty(&dd->fifo_list[WRITE])) + if (!list_empty(&dd->fifo_list[DD_WRITE])) blk_mq_sched_mark_restart_hctx(rq->mq_hctx); spin_unlock_irqrestore(&dd->zone_lock, flags); } @@ -626,8 +628,8 @@ static ssize_t __FUNC(struct elevator_queue *e, char *page) \ __data = jiffies_to_msecs(__data); \ return deadline_var_show(__data, (page)); \ } -SHOW_FUNCTION(deadline_read_expire_show, dd->fifo_expire[READ], 1); -SHOW_FUNCTION(deadline_write_expire_show, dd->fifo_expire[WRITE], 1); +SHOW_FUNCTION(deadline_read_expire_show, dd->fifo_expire[DD_READ], 1); +SHOW_FUNCTION(deadline_write_expire_show, dd->fifo_expire[DD_WRITE], 1); SHOW_FUNCTION(deadline_writes_starved_show, dd->writes_starved, 0); SHOW_FUNCTION(deadline_front_merges_show, dd->front_merges, 0); SHOW_FUNCTION(deadline_fifo_batch_show, dd->fifo_batch, 0); @@ -649,8 +651,8 @@ static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count) *(__PTR) = __data; \ return count; \ } -STORE_FUNCTION(deadline_read_expire_store, &dd->fifo_expire[READ], 0, INT_MAX, 1); -STORE_FUNCTION(deadline_write_expire_store, &dd->fifo_expire[WRITE], 0, INT_MAX, 1); +STORE_FUNCTION(deadline_read_expire_store, &dd->fifo_expire[DD_READ], 0, INT_MAX, 1); +STORE_FUNCTION(deadline_write_expire_store, &dd->fifo_expire[DD_WRITE], 0, INT_MAX, 1); STORE_FUNCTION(deadline_writes_starved_store, &dd->writes_starved, INT_MIN, INT_MAX, 0); STORE_FUNCTION(deadline_front_merges_store, &dd->front_merges, 0, 1, 0); STORE_FUNCTION(deadline_fifo_batch_store, &dd->fifo_batch, 0, INT_MAX, 0); @@ -717,8 +719,8 @@ static int deadline_##name##_next_rq_show(void *data, \ __blk_mq_debugfs_rq_show(m, rq); \ return 0; \ } -DEADLINE_DEBUGFS_DDIR_ATTRS(READ, read) -DEADLINE_DEBUGFS_DDIR_ATTRS(WRITE, write) +DEADLINE_DEBUGFS_DDIR_ATTRS(DD_READ, read) +DEADLINE_DEBUGFS_DDIR_ATTRS(DD_WRITE, write) #undef DEADLINE_DEBUGFS_DDIR_ATTRS static int deadline_batching_show(void *data, struct seq_file *m)

[09/14] block/mq-deadline: Improve compile-time argument checking

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