From patchwork Mon Oct 29 08:49:08 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "jianchao.wang" X-Patchwork-Id: 10658851 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 B1B5313B5 for ; Mon, 29 Oct 2018 08:49:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A58F029724 for ; Mon, 29 Oct 2018 08:49:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9A21229730; Mon, 29 Oct 2018 08:49:56 +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 1B3B129724 for ; Mon, 29 Oct 2018 08:49:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729418AbeJ2RhI (ORCPT ); Mon, 29 Oct 2018 13:37:08 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:36674 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729343AbeJ2RhI (ORCPT ); Mon, 29 Oct 2018 13:37:08 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w9T8nK1J030773; Mon, 29 Oct 2018 08:49:23 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=J7hzrmRyP/DeIBJ0y33e7T6MdMhAdvKFF9gj5cwGn8A=; b=V7jHkB176GRoQSoIMWjxGfYzmZvzsn4G8Ri3YpGLEycPT4TZhqV4Ot0lXjYuexfrVCVQ jCbccjVPMbmGJdQtGKYufzaMbYUJHXNfxYF6qM4oBVmTk+3JWDCm6UqFlFgv3DbeUbFb NRlD/mclHDigD0kkM6HxtpA/zsPzvIA8D9oLqcph0jrFHxecI8xiH4Yi+asK4o9UoIGN LYtNEq3Aiv+nf8aLbuXcXWPbMe3X08ThzMsvzH4Vvm+9m69kllUxUI67byjS7zskj5xV nGaDC8CZ8tioiOoAKh0WXkDox1JGClYZu85+EO4Qq40fzYR7oFU6DzwJMIUQ2FPo9iNU hQ== Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by userp2130.oracle.com with ESMTP id 2nduckrxpq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 29 Oct 2018 08:49:23 +0000 Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id w9T8nMxt003013 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 29 Oct 2018 08:49:22 GMT Received: from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w9T8nMTB004540; Mon, 29 Oct 2018 08:49:22 GMT Received: from will-ThinkCentre-M93p.cn.oracle.com (/10.182.70.234) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 29 Oct 2018 01:49:21 -0700 From: Jianchao Wang To: axboe@kernel.dk Cc: ming.lei@redhat.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH V3 1/4] blk-mq: refactor the code of issue request directly Date: Mon, 29 Oct 2018 16:49:08 +0800 Message-Id: <1540802951-5408-2-git-send-email-jianchao.w.wang@oracle.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1540802951-5408-1-git-send-email-jianchao.w.wang@oracle.com> References: <1540802951-5408-1-git-send-email-jianchao.w.wang@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9060 signatures=668683 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=8.0.1-1807170000 definitions=main-1810290085 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 which is able to handle the return value from .queue_rq callback. To make the code clearer, introduce new helpers blk_mq_make_decision and enum mq_decision. Signed-off-by: Jianchao Wang --- block/blk-mq.c | 104 +++++++++++++++++++++++++++++++++------------------------ 1 file changed, 60 insertions(+), 44 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index dcf10e3..0f6328b 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1711,7 +1711,6 @@ static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx, switch (ret) { case BLK_STS_OK: blk_mq_update_dispatch_busy(hctx, false); - *cookie = new_cookie; break; case BLK_STS_RESOURCE: case BLK_STS_DEV_RESOURCE: @@ -1720,86 +1719,103 @@ static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx, break; default: blk_mq_update_dispatch_busy(hctx, false); - *cookie = BLK_QC_T_NONE; + new_cookie = BLK_QC_T_NONE; break; } + if (cookie) + *cookie = new_cookie; return ret; } -static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, +enum mq_decision { + MQ_INSERT_QUEUE, + MQ_END_REQUEST, + MQ_DO_NOTHING, +}; + +static inline enum mq_decision + blk_mq_make_dicision(blk_status_t ret, bool bypass_insert) +{ + enum mq_decision dec; + + switch(ret) { + case BLK_STS_OK: + dec = MQ_DO_NOTHING; + break; + case BLK_STS_DEV_RESOURCE: + case BLK_STS_RESOURCE: + dec = bypass_insert ? MQ_DO_NOTHING : MQ_INSERT_QUEUE; + break; + default: + dec = bypass_insert ? MQ_DO_NOTHING : MQ_END_REQUEST; + break; + } + + return dec; +} + +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) { struct request_queue *q = rq->q; bool run_queue = true; + enum mq_decision dec; + blk_status_t ret = BLK_STS_RESOURCE; + int srcu_idx; + 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)) { run_queue = false; bypass_insert = false; - goto insert; + goto out_unlock; } if (q->elevator && !bypass_insert) - goto insert; + 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); -insert: - if (bypass_insert) - return BLK_STS_RESOURCE; - - 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_issue_directly(hctx, rq, cookie); +out_unlock: + hctx_unlock(hctx, srcu_idx); - ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false); - 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) + dec = blk_mq_make_dicision(ret, bypass_insert); + switch(dec) { + case MQ_INSERT_QUEUE: + blk_mq_sched_insert_request(rq, false, run_queue, false); + break; + case MQ_END_REQUEST: blk_mq_end_request(rq, ret); + break; + default: + return ret; + } - hctx_unlock(hctx, srcu_idx); + return BLK_STS_OK; } blk_status_t blk_mq_request_issue_directly(struct request *rq) { - blk_status_t ret; - int srcu_idx; - blk_qc_t unused_cookie; struct blk_mq_ctx *ctx = rq->mq_ctx; struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(rq->q, ctx->cpu); - hctx_lock(hctx, &srcu_idx); - ret = __blk_mq_try_issue_directly(hctx, rq, &unused_cookie, true); - hctx_unlock(hctx, srcu_idx); - - return ret; + return blk_mq_try_issue_directly(hctx, rq, NULL, true); } void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, @@ -1921,13 +1937,13 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) data.hctx = blk_mq_map_queue(q, same_queue_rq->mq_ctx->cpu); blk_mq_try_issue_directly(data.hctx, same_queue_rq, - &cookie); + &cookie, false); } } 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); } else { blk_mq_put_ctx(data.ctx); blk_mq_bio_to_request(rq, bio);