From patchwork Fri Dec 7 03:09:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "jianchao.wang" X-Patchwork-Id: 10717391 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 3F4C413AF for ; Fri, 7 Dec 2018 03:10:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3078E2E944 for ; Fri, 7 Dec 2018 03:10:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 24FCE2E9AB; Fri, 7 Dec 2018 03:10:54 +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 972F12E944 for ; Fri, 7 Dec 2018 03:10:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726039AbeLGDKc (ORCPT ); Thu, 6 Dec 2018 22:10:32 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:60962 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726022AbeLGDKb (ORCPT ); Thu, 6 Dec 2018 22:10:31 -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 wB72x1PW177228; Fri, 7 Dec 2018 03:10:28 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=MiJ0eHjm0z5juPu6Vb83GsMn2AocDMhet+vwBF8v2mE=; b=RB77gS6rAX6DiNoD6SeNd2zekfwt+IToh5PJ9PBWfN9XE5tW0SYABxyxLDZox3Lhp1oK vtPR/G1FPFiB0mCuqp+bCODyamQ2DemH8req/CRAvEnuv+kQ0TWIq4zs8QLsMluArdtE IFfNHGtyWtmiGxFpGzB9xNtg7kTUf8PEj8lnL8jXaKYhbEPXIwQniEL962cSXH7sxLr2 jGw35GeV3A+8fINdowphAQmeFOiGR28oLKA/WGhiK9fe2UBfE4rPKtuiqYVsWUmmZ828 +pRA4F8wHV4T3AhIqgfjnXUXco5MRj/rkYRe1uL1PixGxKUBv0TyuNw4avth0UQtVzTn MQ== Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by userp2120.oracle.com with ESMTP id 2p3jxrufq8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 07 Dec 2018 03:10:28 +0000 Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id wB73ARpU014655 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 7 Dec 2018 03:10:27 GMT Received: from abhmp0005.oracle.com (abhmp0005.oracle.com [141.146.116.11]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id wB73ARKj032569; Fri, 7 Dec 2018 03:10:27 GMT Received: from will-ThinkCentre-M93p.cn.oracle.com (/10.182.70.234) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 06 Dec 2018 19:10:27 -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 V11 2/4] blk-mq: refactor the code of issue request directly Date: Fri, 7 Dec 2018 11:09:43 +0800 Message-Id: <1544152185-32667-3-git-send-email-jianchao.w.wang@oracle.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1544152185-32667-1-git-send-email-jianchao.w.wang@oracle.com> References: <1544152185-32667-1-git-send-email-jianchao.w.wang@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9099 signatures=668679 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-1812070024 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 | 120 ++++++++++++++++++++++++++++----------------------------- 1 file changed, 59 insertions(+), 61 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 01802bf..88ee447 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1815,92 +1815,90 @@ 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 and return + * BLK_STS_OK for 'bypass == true' case, otherwise, + * the caller will fail forever. + */ + force = bypass; + 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. - */ - force = bypass_insert; - 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; + /* + * If the request is issued unsuccessfully with + * BLK_STS_DEV_RESOURCE or BLK_STS_RESOURCE, insert + * the request to hctx dispatch list due to attached + * lldd resource. + */ + force = true; + 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 = bypass ? BLK_STS_OK : ret; + } else if (!bypass) { + blk_mq_sched_insert_request(rq, false, + run_queue, false); + } + break; + default: + if (!bypass) + blk_mq_end_request(rq, ret); + 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, @@ -2043,13 +2041,13 @@ 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);