From patchwork Thu May 27 01:01:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 12283113 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0135C47082 for ; Thu, 27 May 2021 01:01:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD18C613CC for ; Thu, 27 May 2021 01:01:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233788AbhE0BD1 (ORCPT ); Wed, 26 May 2021 21:03:27 -0400 Received: from mail-pl1-f172.google.com ([209.85.214.172]:43594 "EHLO mail-pl1-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233801AbhE0BD1 (ORCPT ); Wed, 26 May 2021 21:03:27 -0400 Received: by mail-pl1-f172.google.com with SMTP id v12so1489699plo.10 for ; Wed, 26 May 2021 18:01:54 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=/9lr2FlM8aPVNr8W5stKehP5sCAwrhh9DM0XcB/Dpj4=; b=atiasqZzlSmlHBkTyjSeLxo6f0d3JtZS5r9BZWQQ6h1gmt76MaUqdnzmMHJd7+HHyU 3mIoubKpbVo0eKrTzP+3U2w/YLZaBCvwxEbbEiwBCl3P8Hc1ODBKTiuBfJ3LQHZNWq37 NthZh6at5Saoa59fW06i454XvDHtrNXNtdoVQ/h/q7uclIDxwY4VqZBwpzqovxTqa512 lNIQV2U/j4EpzSjXEmDxO4OiFL+TU1MetB/HRE202KcBIAvXasBt/8NfTkXwWDXSqwUn iCZdqpAoUp8CFM9LMJbjJG9yUdpBajf3smdWkCkU+9dVY4WigpyXt6+ySpOkQaGF1nMO RtSA== X-Gm-Message-State: AOAM5331VS5zUHHbhUN7visyuntDTvKP90ACjin4fSAdFjaqLG8HCQz+ Bp/4iD9ozjpsqqSJQPn9r9Y= X-Google-Smtp-Source: ABdhPJy1dXqu6+8aniIUpGofx4tJknaZ/a5UT7JWbpeKof3OAafdfLV/u1MzJWAYi4bj7oKA2OcbXw== X-Received: by 2002:a17:90a:3041:: with SMTP id q1mr6693684pjl.191.1622077313874; Wed, 26 May 2021 18:01:53 -0700 (PDT) Received: from asus.hsd1.ca.comcast.net (c-73-241-217-19.hsd1.ca.comcast.net. [73.241.217.19]) by smtp.gmail.com with ESMTPSA id j22sm310707pfd.215.2021.05.26.18.01.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 26 May 2021 18:01:53 -0700 (PDT) From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Jaegeuk Kim , Adam Manzanares , Bart Van Assche , Damien Le Moal , Ming Lei Subject: [PATCH 5/9] block/mq-deadline: Improve compile-time argument checking Date: Wed, 26 May 2021 18:01:30 -0700 Message-Id: <20210527010134.32448-6-bvanassche@acm.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210527010134.32448-1-bvanassche@acm.org> References: <20210527010134.32448-1-bvanassche@acm.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Modern compilers complain if an out-of-range value is passed to a function argument that has an enumeration type. Let the compiler detect out-of-range data direction arguments instead of verifying the data_dir argument at runtime. Cc: Damien Le Moal Cc: Christoph Hellwig Cc: Ming Lei Signed-off-by: Bart Van Assche Reviewed-by: Chaitanya Kulkarni Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Reviewed-by: Himanshu Madhani --- block/mq-deadline.c | 96 +++++++++++++++++++++++---------------------- 1 file changed, 49 insertions(+), 47 deletions(-) diff --git a/block/mq-deadline.c b/block/mq-deadline.c index c4f51e7884fb..dfbc6b77fa71 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, +} __packed; + +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)