From patchwork Tue Nov 13 18:57:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keith Busch X-Patchwork-Id: 10681393 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 9DCB913BF for ; Tue, 13 Nov 2018 19:00:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 941D62B38C for ; Tue, 13 Nov 2018 19:00:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 882572B3E6; Tue, 13 Nov 2018 19:00:53 +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 2C4762B3B4 for ; Tue, 13 Nov 2018 19:00:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725794AbeKNFAR (ORCPT ); Wed, 14 Nov 2018 00:00:17 -0500 Received: from mga01.intel.com ([192.55.52.88]:64226 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725750AbeKNFAR (ORCPT ); Wed, 14 Nov 2018 00:00:17 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Nov 2018 11:00:51 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,229,1539673200"; d="scan'208";a="96018832" Received: from unknown (HELO localhost.lm.intel.com) ([10.232.112.69]) by FMSMGA003.fm.intel.com with ESMTP; 13 Nov 2018 11:00:51 -0800 From: Keith Busch To: linux-scsi@vger.kernel.org, linux-block@vger.kernel.org Cc: Keith Busch Subject: [PATCH 2/2] blk-mq: Simplify request completion state Date: Tue, 13 Nov 2018 11:57:12 -0700 Message-Id: <20181113185712.10063-2-keith.busch@intel.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20181113185712.10063-1-keith.busch@intel.com> References: <20181113185712.10063-1-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 03b1af0151ca..6c546a021803 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -568,9 +568,7 @@ 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 e32e9293e5a0..1a857c6e17fa 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -237,20 +237,6 @@ void blk_mq_quiesce_queue_nowait(struct request_queue *q); unsigned int blk_mq_rq_cpu(struct request *rq); -/** - * 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.