From patchwork Mon Oct 2 07:15:32 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Damien Le Moal X-Patchwork-Id: 9980313 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E945160365 for ; Mon, 2 Oct 2017 07:15:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DB87C2022B for ; Mon, 2 Oct 2017 07:15:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D076F27FBC; Mon, 2 Oct 2017 07:15:52 +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=-6.9 required=2.0 tests=BAYES_00,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 7BC592022B for ; Mon, 2 Oct 2017 07:15:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751252AbdJBHPu (ORCPT ); Mon, 2 Oct 2017 03:15:50 -0400 Received: from esa2.hgst.iphmx.com ([68.232.143.124]:22502 "EHLO esa2.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750773AbdJBHPu (ORCPT ); Mon, 2 Oct 2017 03:15:50 -0400 X-IronPort-AV: E=Sophos;i="5.42,468,1500912000"; d="scan'208";a="151954159" Received: from sjappemgw11.hgst.com (HELO sjappemgw12.hgst.com) ([199.255.44.62]) by ob1.hgst.iphmx.com with ESMTP; 02 Oct 2017 15:24:05 +0800 Received: from washi.fujisawa.hgst.com ([10.149.53.254]) by sjappemgw12.hgst.com with ESMTP; 02 Oct 2017 00:15:49 -0700 From: Damien Le Moal To: linux-scsi@vger.kernel.org, "Martin K . Petersen" , linux-block@vger.kernel.org, Jens Axboe Cc: Christoph Hellwig , Bart Van Assche Subject: [PATCH V6 11/14] blokc: mq-deadline: Introduce dispatch helpers Date: Mon, 2 Oct 2017 16:15:32 +0900 Message-Id: <20171002071535.8007-12-damien.lemoal@wdc.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20171002071535.8007-1-damien.lemoal@wdc.com> References: <20171002071535.8007-1-damien.lemoal@wdc.com> 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 Avoid directly referencing the next_rq and fifo_list arrays using the helper functions deadline_next_request() and deadline_fifo_request() to facilitate changes in the dispatch request selection in __dd_dispatch_request(). Signed-off-by: Damien Le Moal Reviewed-by: Bart Van Assche --- block/mq-deadline.c | 45 +++++++++++++++++++++++++++++++++++++-------- 1 file changed, 37 insertions(+), 8 deletions(-) diff --git a/block/mq-deadline.c b/block/mq-deadline.c index f0c01ef934b4..6b7b84ee8f82 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -194,13 +194,42 @@ static inline int deadline_check_fifo(struct deadline_data *dd, int ddir) } /* + * For the specified data direction, return the next request to + * dispatch using arrival ordered lists. + */ +static struct request * +deadline_fifo_request(struct deadline_data *dd, int data_dir) +{ + if (WARN_ON_ONCE(data_dir != READ && data_dir != WRITE)) + return NULL; + + if (list_empty(&dd->fifo_list[data_dir])) + return NULL; + + return rq_entry_fifo(dd->fifo_list[data_dir].next); +} + +/* + * For the specified data direction, return the next request to + * dispatch using sector position sorted lists. + */ +static struct request * +deadline_next_request(struct deadline_data *dd, int data_dir) +{ + if (WARN_ON_ONCE(data_dir != READ && data_dir != WRITE)) + return NULL; + + return dd->next_rq[data_dir]; +} + +/* * deadline_dispatch_requests selects the best request according to * read/write expire, fifo_batch, etc */ static struct request *__dd_dispatch_request(struct blk_mq_hw_ctx *hctx) { struct deadline_data *dd = hctx->queue->elevator->elevator_data; - struct request *rq; + struct request *rq, *next_rq; bool reads, writes; int data_dir; @@ -216,10 +245,9 @@ static struct request *__dd_dispatch_request(struct blk_mq_hw_ctx *hctx) /* * batches are currently reads XOR writes */ - if (dd->next_rq[WRITE]) - rq = dd->next_rq[WRITE]; - else - rq = dd->next_rq[READ]; + rq = deadline_next_request(dd, WRITE); + if (!rq) + rq = deadline_next_request(dd, READ); if (rq && dd->batching < dd->fifo_batch) /* we have a next request are still entitled to batch */ @@ -262,19 +290,20 @@ static struct request *__dd_dispatch_request(struct blk_mq_hw_ctx *hctx) /* * we are not running a batch, find best request for selected data_dir */ - if (deadline_check_fifo(dd, data_dir) || !dd->next_rq[data_dir]) { + next_rq = deadline_next_request(dd, data_dir); + if (deadline_check_fifo(dd, data_dir) || !next_rq) { /* * A deadline has expired, the last request was in the other * direction, or we have run out of higher-sectored requests. * Start again from the request with the earliest expiry time. */ - rq = rq_entry_fifo(dd->fifo_list[data_dir].next); + rq = deadline_fifo_request(dd, data_dir); } else { /* * The last req was the same dir and we have a next request in * sort order. No expired requests so continue on from here. */ - rq = dd->next_rq[data_dir]; + rq = next_rq; } dd->batching = 0;