From patchwork Tue Aug 7 17:44:32 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 10559007 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CB39D15E9 for ; Tue, 7 Aug 2018 17:47:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BF05928749 for ; Tue, 7 Aug 2018 17:47:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B258F2A65E; Tue, 7 Aug 2018 17:47:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 337FB2A591 for ; Tue, 7 Aug 2018 17:47:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403837AbeHGUDL (ORCPT ); Tue, 7 Aug 2018 16:03:11 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:55358 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2403794AbeHGUDL (ORCPT ); Tue, 7 Aug 2018 16:03:11 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6797F8197022; Tue, 7 Aug 2018 17:47:44 +0000 (UTC) Received: from localhost (ovpn-12-77.pek2.redhat.com [10.72.12.77]) by smtp.corp.redhat.com (Postfix) with ESMTP id EEB3910073B5; Tue, 7 Aug 2018 17:47:30 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Ming Lei , Alan Stern , Christoph Hellwig , Bart Van Assche , Jianchao Wang , Hannes Reinecke , Johannes Thumshirn , Adrian Hunter , "James E.J. Bottomley" , "Martin K. Petersen" , linux-scsi@vger.kernel.org Subject: [RFC PATCH 13/14] block: simplify runtime PM support Date: Wed, 8 Aug 2018 01:44:32 +0800 Message-Id: <20180807174433.8374-14-ming.lei@redhat.com> In-Reply-To: <20180807174433.8374-1-ming.lei@redhat.com> References: <20180807174433.8374-1-ming.lei@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Tue, 07 Aug 2018 17:47:44 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Tue, 07 Aug 2018 17:47:44 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'ming.lei@redhat.com' RCPT:'' Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch simplifies runtime PM support by the following approach: 1) resume device in blk_queue_enter() if this device isn't active 2) freeze queue in blk_pre_runtime_suspend() 3) unfreeze queue in blk_pre_runtime_resume() 4) remove checking on RRF_PM because now we requires out-of-band PM request to resume device Then we can remove blk_pm_allow_request(), and more importantly this way can be applied to blk-mq path too. Cc: Alan Stern Cc: Christoph Hellwig Cc: Bart Van Assche Cc: Jianchao Wang Cc: Hannes Reinecke Cc: Johannes Thumshirn Cc: Adrian Hunter Cc: "James E.J. Bottomley" Cc: "Martin K. Petersen" Cc: linux-scsi@vger.kernel.org Signed-off-by: Ming Lei --- block/blk-core.c | 72 ++++++++++++++++++++++++++----------------------- block/elevator.c | 7 +++-- drivers/scsi/scsi_lib.c | 7 +++++ include/linux/blkdev.h | 2 ++ 4 files changed, 51 insertions(+), 37 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index ea12e3fcfa11..7390149f4fd1 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -884,6 +884,24 @@ struct request_queue *blk_alloc_queue(gfp_t gfp_mask) } EXPORT_SYMBOL(blk_alloc_queue); +#ifdef CONFIG_PM +static void blk_resume_queue(struct request_queue *q) +{ + if (!q->dev) + return; + + /* PM request needs to be dealt with out of band */ + mutex_lock(&q->pm_lock); + if (q->rpm_status == RPM_SUSPENDED || q->rpm_status == RPM_SUSPENDING) + pm_runtime_resume(q->dev); + mutex_unlock(&q->pm_lock); +} +#else +static void blk_resume_queue(struct request_queue *q) +{ +} +#endif + /** * blk_queue_enter() - try to increase q->q_usage_counter * @q: request queue pointer @@ -907,6 +925,8 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) */ smp_rmb(); + blk_resume_queue(q); + wait_event(q->mq_freeze_wq, atomic_read(&q->mq_freeze_depth) == 0 || blk_queue_dying(q)); @@ -1684,7 +1704,7 @@ EXPORT_SYMBOL_GPL(part_round_stats); #ifdef CONFIG_PM static void blk_pm_put_request(struct request *rq) { - if (rq->q->dev && !(rq->rq_flags & RQF_PM) && !--rq->q->nr_pending) + if (rq->q->dev && !--rq->q->nr_pending) pm_runtime_mark_last_busy(rq->q->dev); } #else @@ -2702,30 +2722,6 @@ void blk_account_io_done(struct request *req, u64 now) } } -#ifdef CONFIG_PM -/* - * Don't process normal requests when queue is suspended - * or in the process of suspending/resuming - */ -static bool blk_pm_allow_request(struct request *rq) -{ - switch (rq->q->rpm_status) { - case RPM_RESUMING: - case RPM_SUSPENDING: - return rq->rq_flags & RQF_PM; - case RPM_SUSPENDED: - return false; - default: - return true; - } -} -#else -static bool blk_pm_allow_request(struct request *rq) -{ - return true; -} -#endif - void blk_account_io_start(struct request *rq, bool new_io) { struct hd_struct *part; @@ -2770,13 +2766,8 @@ static struct request *elv_next_request(struct request_queue *q) WARN_ON_ONCE(q->mq_ops); while (1) { - list_for_each_entry(rq, &q->queue_head, queuelist) { - if (blk_pm_allow_request(rq)) - return rq; - - if (rq->rq_flags & RQF_SOFTBARRIER) - break; - } + list_for_each_entry(rq, &q->queue_head, queuelist) + return rq; /* * Flush request is running and flush request isn't queueable @@ -3737,6 +3728,7 @@ void blk_pm_runtime_init(struct request_queue *q, struct device *dev) return; } + mutex_init(&q->pm_lock); q->dev = dev; q->rpm_status = RPM_ACTIVE; pm_runtime_set_autosuspend_delay(q->dev, -1); @@ -3772,6 +3764,7 @@ int blk_pre_runtime_suspend(struct request_queue *q) if (!q->dev) return ret; + mutex_lock(&q->pm_lock); spin_lock_irq(q->queue_lock); if (q->nr_pending) { ret = -EBUSY; @@ -3780,6 +3773,13 @@ int blk_pre_runtime_suspend(struct request_queue *q) q->rpm_status = RPM_SUSPENDING; } spin_unlock_irq(q->queue_lock); + + if (!ret) { + blk_freeze_queue(q); + q->rpm_q_frozen = true; + } + mutex_unlock(&q->pm_lock); + return ret; } EXPORT_SYMBOL(blk_pre_runtime_suspend); @@ -3854,16 +3854,22 @@ void blk_post_runtime_resume(struct request_queue *q, int err) if (!q->dev) return; + lockdep_assert_held(&q->pm_lock); + spin_lock_irq(q->queue_lock); if (!err) { q->rpm_status = RPM_ACTIVE; - __blk_run_queue(q); pm_runtime_mark_last_busy(q->dev); pm_request_autosuspend(q->dev); } else { q->rpm_status = RPM_SUSPENDED; } spin_unlock_irq(q->queue_lock); + + if (!err && q->rpm_q_frozen) { + blk_mq_unfreeze_queue(q); + q->rpm_q_frozen = false; + } } EXPORT_SYMBOL(blk_post_runtime_resume); diff --git a/block/elevator.c b/block/elevator.c index a34fecbe7e81..d389b942378b 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -560,15 +560,14 @@ void elv_bio_merged(struct request_queue *q, struct request *rq, #ifdef CONFIG_PM static void blk_pm_requeue_request(struct request *rq) { - if (rq->q->dev && !(rq->rq_flags & RQF_PM)) + if (rq->q->dev) rq->q->nr_pending--; } static void blk_pm_add_request(struct request_queue *q, struct request *rq) { - if (q->dev && !(rq->rq_flags & RQF_PM) && q->nr_pending++ == 0 && - (q->rpm_status == RPM_SUSPENDED || q->rpm_status == RPM_SUSPENDING)) - pm_request_resume(q->dev); + if (q->dev) + q->nr_pending++; } #else static inline void blk_pm_requeue_request(struct request *rq) {} diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index c78602f1a425..0aee332fbb63 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -279,6 +279,10 @@ int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, struct scsi_request *rq; int ret = DRIVER_ERROR << 24; struct request_queue *q = sdev->host->admin_q; + bool pm_rq = rq_flags & RQF_PM; + + if (!pm_rq) + scsi_autopm_get_device(sdev); req = blk_get_request(q, data_direction == DMA_TO_DEVICE ? @@ -328,6 +332,9 @@ int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, atomic_dec(&sdev->nr_admin_pending); wake_up_all(&sdev->admin_wq); + if (!pm_rq) + scsi_autopm_put_device(sdev); + return ret; } EXPORT_SYMBOL(__scsi_execute); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index a9d371f55ca5..b3dcba83a8d7 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -544,6 +544,8 @@ struct request_queue { struct device *dev; int rpm_status; unsigned int nr_pending; + bool rpm_q_frozen; + struct mutex pm_lock; #endif /*