From patchwork Mon Oct 2 22:52:16 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 9981305 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 536C860384 for ; Mon, 2 Oct 2017 22:52:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 471E3285EF for ; Mon, 2 Oct 2017 22:52:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3C12B288C5; Mon, 2 Oct 2017 22:52:50 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham 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 4ABAF289E1 for ; Mon, 2 Oct 2017 22:52:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751888AbdJBWws (ORCPT ); Mon, 2 Oct 2017 18:52:48 -0400 Received: from esa4.hgst.iphmx.com ([216.71.154.42]:64544 "EHLO esa4.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751892AbdJBWwr (ORCPT ); Mon, 2 Oct 2017 18:52:47 -0400 X-IronPort-AV: E=Sophos;i="5.42,471,1500912000"; d="scan'208";a="55706973" Received: from sjappemgw11.hgst.com (HELO sjappemgw12.hgst.com) ([199.255.44.62]) by ob1.hgst.iphmx.com with ESMTP; 03 Oct 2017 06:52:48 +0800 Received: from thinkpad-bart.sdcorp.global.sandisk.com (HELO thinkpad-bart.int.fusionio.com) ([10.11.172.152]) by sjappemgw12.hgst.com with ESMTP; 02 Oct 2017 15:52:19 -0700 From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , "Martin K . Petersen" , =Oleksandr Natalenko , "Luis R . Rodriguez" , Bart Van Assche , Ming Lei , Hannes Reinecke , Johannes Thumshirn Subject: [PATCH v5 6/8] scsi: Reduce suspend latency Date: Mon, 2 Oct 2017 15:52:16 -0700 Message-Id: <20171002225218.18548-7-bart.vanassche@wdc.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20171002225218.18548-1-bart.vanassche@wdc.com> References: <20171002225218.18548-1-bart.vanassche@wdc.com> 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 Avoid that it can take 200 ms too long to wait for requests to finish. Note: blk_mq_freeze_queue() uses a wait queue to wait for ongoing requests to finish. Signed-off-by: Bart Van Assche Cc: Martin K. Petersen Cc: Ming Lei Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Johannes Thumshirn --- drivers/scsi/scsi_lib.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 62f905b22821..e0bef5c9dd14 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2927,21 +2927,25 @@ static void scsi_wait_for_queuecommand(struct scsi_device *sdev) int scsi_device_quiesce(struct scsi_device *sdev) { + struct request_queue *q = sdev->request_queue; + bool freeze; int err; mutex_lock(&sdev->state_mutex); + /* + * Do not attempt to freeze the queue of an already quiesced device + * because that could result in a deadlock. + */ + freeze = sdev->sdev_state == SDEV_RUNNING; + if (freeze) + blk_mq_freeze_queue(q); err = scsi_device_set_state(sdev, SDEV_QUIESCE); mutex_unlock(&sdev->state_mutex); - if (err) - return err; + if (freeze) + blk_mq_unfreeze_queue(q); - scsi_run_queue(sdev->request_queue); - while (atomic_read(&sdev->device_busy)) { - msleep_interruptible(200); - scsi_run_queue(sdev->request_queue); - } - return 0; + return err; } EXPORT_SYMBOL(scsi_device_quiesce);