From patchwork Wed Dec 5 07:44:00 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "jianchao.wang" X-Patchwork-Id: 10713103 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 55B98109C for ; Wed, 5 Dec 2018 07:44:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 403732CC2D for ; Wed, 5 Dec 2018 07:44:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 312592CC57; Wed, 5 Dec 2018 07:44:57 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY 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 A1FC62CC2D for ; Wed, 5 Dec 2018 07:44:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726874AbeLEHoy (ORCPT ); Wed, 5 Dec 2018 02:44:54 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:43102 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727328AbeLEHox (ORCPT ); Wed, 5 Dec 2018 02:44:53 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id wB57i48r129835; Wed, 5 Dec 2018 07:44:50 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2018-07-02; bh=CQZ6XaLgDcM57YO2cVSVXHzhyMl0Ti+QXzcKCbaYUys=; b=HQB+GSSCP9SH76dlZyOHjmabYneExCmnVmP/zj8ixkuknPsSODltoEDeVqZ8vh0fbySt cnaJtVENcOUONHoGFDAVR7R/J8O48qSaHcVW3z3D//ujcmYDEgDO95CX8pDU4PxzLiug IjfIk39q/j8L0X943dV3q9WIusF3RVtXgmrAhVyf0YbPlifTrRT+5I+Uz4X24kf3yfZs OE7Q8SBQ70gEULsnVLMNeQId11Nw9Vs4xFmwQopbpLy9qhKDb9ZGEe0W1jub8DdJ83Vj 404Nu+cldLm34Hd1T5zT6ibJPh/WMtO2xEdCPNYvfBPmBvQ/gCKVFl/UlnXJh6cYTymW sw== Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by userp2120.oracle.com with ESMTP id 2p3jxrgpw4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 05 Dec 2018 07:44:49 +0000 Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id wB57ihDd009942 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 5 Dec 2018 07:44:44 GMT Received: from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id wB57ihFK029665; Wed, 5 Dec 2018 07:44:43 GMT Received: from will-ThinkCentre-M93p.cn.oracle.com (/10.182.70.234) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 04 Dec 2018 23:44:42 -0800 From: Jianchao Wang To: axboe@kernel.dk Cc: ming.lei@redhat.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH V9 2/4] blk-mq: refactor the code of issue request directly Date: Wed, 5 Dec 2018 15:44:00 +0800 Message-Id: <1543995842-20704-3-git-send-email-jianchao.w.wang@oracle.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1543995842-20704-1-git-send-email-jianchao.w.wang@oracle.com> References: <1543995842-20704-1-git-send-email-jianchao.w.wang@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9097 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1812050072 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 Merge blk_mq_try_issue_directly and __blk_mq_try_issue_directly into one interface to unify the interfaces to issue requests directly. The merged interface takes over the requests totally, it could insert, end or do nothing based on the return value of .queue_rq and 'bypass' parameter. Then caller needn't any other handling any more and then code could be cleaned up. Signed-off-by: Jianchao Wang --- block/blk-mq.c | 116 +++++++++++++++++++++++++++------------------------------ 1 file changed, 54 insertions(+), 62 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 153af90..fe92e52 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1815,93 +1815,85 @@ static bool blk_rq_can_direct_dispatch(struct request *rq) return req_op(rq) == REQ_OP_READ || req_op(rq) == REQ_OP_WRITE; } -static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, +static blk_status_t blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, struct request *rq, blk_qc_t *cookie, - bool bypass_insert, bool last) + bool bypass, bool last) { struct request_queue *q = rq->q; bool run_queue = true; + blk_status_t ret = BLK_STS_RESOURCE; + int srcu_idx; bool force = false; + if (!blk_rq_can_direct_dispatch(rq)) { + /* + * Insert request to hctx dispatch list for 'bypass == true' + * case, otherwise, the caller will fail forever. + */ + if (bypass) + force = true; + goto out; + } + + hctx_lock(hctx, &srcu_idx); /* - * RCU or SRCU read lock is needed before checking quiesced flag. + * hctx_lock is needed before checking quiesced flag. * - * When queue is stopped or quiesced, ignore 'bypass_insert' from - * blk_mq_request_issue_directly(), and return BLK_STS_OK to caller, - * and avoid driver to try to dispatch again. + * When queue is stopped or quiesced, ignore 'bypass', insert + * and return BLK_STS_OK to caller, and avoid driver to try to + * dispatch again. */ - if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)) { + if (unlikely(blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q))) { run_queue = false; - bypass_insert = false; - goto insert; + bypass = false; + goto out_unlock; } - if (q->elevator && !bypass_insert) - goto insert; - - if (!blk_rq_can_direct_dispatch(rq)) { - /* - * For 'bypass_insert == true' case, insert request into hctx - * dispatch list. - */ - if (bypass_insert) - force = true; - goto insert; - } + if (unlikely(q->elevator && !bypass)) + goto out_unlock; if (!blk_mq_get_dispatch_budget(hctx)) - goto insert; + goto out_unlock; if (!blk_mq_get_driver_tag(rq)) { blk_mq_put_dispatch_budget(hctx); - goto insert; + goto out_unlock; } - return __blk_mq_issue_directly(hctx, rq, cookie, last); -insert: - if (force) { - blk_mq_request_bypass_insert(rq, run_queue); - return BLK_STS_OK; - } else if (bypass_insert) { - return BLK_STS_RESOURCE; + ret = __blk_mq_issue_directly(hctx, rq, cookie, last); +out_unlock: + hctx_unlock(hctx, srcu_idx); +out: + switch (ret) { + case BLK_STS_OK: + break; + case BLK_STS_DEV_RESOURCE: + case BLK_STS_RESOURCE: + if (force) { + blk_mq_request_bypass_insert(rq, run_queue); + ret = BLK_STS_OK; + } else if (!bypass) { + blk_mq_sched_insert_request(rq, false, run_queue, false); + ret = BLK_STS_OK; + } + break; + default: + if (!bypass) { + blk_mq_end_request(rq, ret); + ret = BLK_STS_OK; + } + break; } - blk_mq_sched_insert_request(rq, false, run_queue, false); - return BLK_STS_OK; -} - -static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, - struct request *rq, blk_qc_t *cookie) -{ - blk_status_t ret; - int srcu_idx; - - might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING); - - hctx_lock(hctx, &srcu_idx); - - ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false, true); - if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) - blk_mq_sched_insert_request(rq, false, true, false); - else if (ret != BLK_STS_OK) - blk_mq_end_request(rq, ret); - - hctx_unlock(hctx, srcu_idx); + return ret; } blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last) { - blk_status_t ret; - int srcu_idx; - blk_qc_t unused_cookie; - struct blk_mq_hw_ctx *hctx = rq->mq_hctx; + blk_qc_t unused; - hctx_lock(hctx, &srcu_idx); - ret = __blk_mq_try_issue_directly(hctx, rq, &unused_cookie, true, last); - hctx_unlock(hctx, srcu_idx); - - return ret; + return blk_mq_try_issue_directly(rq->mq_hctx, rq, &unused, true, last); } void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, @@ -2044,13 +2036,13 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) if (same_queue_rq) { data.hctx = same_queue_rq->mq_hctx; blk_mq_try_issue_directly(data.hctx, same_queue_rq, - &cookie); + &cookie, false, true); } } else if ((q->nr_hw_queues > 1 && is_sync) || (!q->elevator && !data.hctx->dispatch_busy)) { blk_mq_put_ctx(data.ctx); blk_mq_bio_to_request(rq, bio); - blk_mq_try_issue_directly(data.hctx, rq, &cookie); + blk_mq_try_issue_directly(data.hctx, rq, &cookie, false, true); } else { blk_mq_put_ctx(data.ctx); blk_mq_bio_to_request(rq, bio);