From patchwork Thu Jul 5 13:24:09 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wen-chien Jesse Sung X-Patchwork-Id: 939930 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 41Lz9829Lgz9s3q; Thu, 5 Jul 2018 23:24:28 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1fb4FC-00077w-56; Thu, 05 Jul 2018 13:24:22 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.86_2) (envelope-from ) id 1fb4F8-000759-Md for kernel-team@lists.ubuntu.com; Thu, 05 Jul 2018 13:24:18 +0000 Received: from 1.general.jesse.us.vpn ([10.172.69.96] helo=cola.voip.idv.tw) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1fb4F7-0008EE-Sc; Thu, 05 Jul 2018 13:24:18 +0000 From: Wen-chien Jesse Sung To: kernel-team@lists.ubuntu.com Subject: [Bionic][PATCH 2/3] block, bfq: remove batches of confusing ifdefs Date: Thu, 5 Jul 2018 21:24:09 +0800 Message-Id: <20180705132410.5723-3-jesse.sung@canonical.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180705132410.5723-1-jesse.sung@canonical.com> References: <20180705132410.5723-1-jesse.sung@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Paolo Valente BugLink: https://launchpad.net/bugs/1780066 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 Tested-by: Luca Miccio Signed-off-by: Paolo Valente Signed-off-by: Jens Axboe (cherry picked from commit 9b25bd0368d562d1929059e8eb9de4102567b923) Signed-off-by: Wen-chien Jesse Sung --- 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 6da7f7131b95..eda5cc0843be 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 void bfq_update_dispatch_stats(struct request_queue *q, + struct request *rq, + 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(q->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(q->queue_lock); +} +#else +static inline void bfq_update_dispatch_stats(struct request_queue *q, + struct request *rq, + 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(hctx->queue, rq, 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 void bfq_update_insert_stats(struct request_queue *q, + struct bfq_queue *bfqq, + 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(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); +} +#else +static inline void bfq_update_insert_stats(struct request_queue *q, + struct bfq_queue *bfqq, + 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(q, bfqq, idle_timer_disabled, + cmd_flags); } static void bfq_insert_requests(struct blk_mq_hw_ctx *hctx,