From patchwork Thu Nov 15 17:56:26 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keith Busch X-Patchwork-Id: 10684783 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 8905C3CF1 for ; Thu, 15 Nov 2018 17:59:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7AC712CEA2 for ; Thu, 15 Nov 2018 17:59:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6E9B32CE14; Thu, 15 Nov 2018 17:59:53 +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=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 15E0E2CEA2 for ; Thu, 15 Nov 2018 17:59:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388661AbeKPEIl (ORCPT ); Thu, 15 Nov 2018 23:08:41 -0500 Received: from mga11.intel.com ([192.55.52.93]:61131 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726453AbeKPEIl (ORCPT ); Thu, 15 Nov 2018 23:08:41 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Nov 2018 09:59:51 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,237,1539673200"; d="scan'208";a="280206598" Received: from unknown (HELO localhost.lm.intel.com) ([10.232.112.69]) by fmsmga005.fm.intel.com with ESMTP; 15 Nov 2018 09:59:51 -0800 From: Keith Busch To: linux-scsi@vger.kernel.org, linux-block@vger.kernel.org Cc: Jens Axboe , Martin Petersen , Bart Van Assche , Keith Busch Subject: [PATCH 3/3] blk-mq: Simplify request completion state Date: Thu, 15 Nov 2018 10:56:26 -0700 Message-Id: <20181115175626.13293-3-keith.busch@intel.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20181115175626.13293-1-keith.busch@intel.com> References: <20181115175626.13293-1-keith.busch@intel.com> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP There are no more users relying on blk-mq request states to prevent double completions, so replace the relatively expensive cmpxchg operation with WRITE_ONCE. Signed-off-by: Keith Busch --- block/blk-mq.c | 4 +--- include/linux/blk-mq.h | 14 -------------- 2 files changed, 1 insertion(+), 17 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index f91951800a64..9d569e74cbe3 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -565,9 +565,7 @@ static void __blk_mq_complete_request(struct request *rq) bool shared = false; int cpu; - if (!blk_mq_mark_complete(rq)) - return; - + WRITE_ONCE(rq->state, MQ_RQ_COMPLETE); /* * Most of single queue controllers, there is only one irq vector * for handling IO completion, and the only irq's affinity is set diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index dec6ef385492..ec0a2688a373 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -293,20 +293,6 @@ void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues); void blk_mq_quiesce_queue_nowait(struct request_queue *q); -/** - * blk_mq_mark_complete() - Set request state to complete - * @rq: request to set to complete state - * - * Returns true if request state was successfully set to complete. If - * successful, the caller is responsibile for seeing this request is ended, as - * blk_mq_complete_request will not work again. - */ -static inline bool blk_mq_mark_complete(struct request *rq) -{ - return cmpxchg(&rq->state, MQ_RQ_IN_FLIGHT, MQ_RQ_COMPLETE) == - MQ_RQ_IN_FLIGHT; -} - /* * Driver command data is immediately after the request. So subtract request * size to get back to the original request, add request size to get the PDU.