From patchwork Thu Dec 16 16:05:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jens Axboe X-Patchwork-Id: 12681551 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1BC52C433FE for ; Thu, 16 Dec 2021 16:05:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232897AbhLPQFm (ORCPT ); Thu, 16 Dec 2021 11:05:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238786AbhLPQFm (ORCPT ); Thu, 16 Dec 2021 11:05:42 -0500 Received: from mail-io1-xd2f.google.com (mail-io1-xd2f.google.com [IPv6:2607:f8b0:4864:20::d2f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EADD2C061574 for ; Thu, 16 Dec 2021 08:05:41 -0800 (PST) Received: by mail-io1-xd2f.google.com with SMTP id p23so35810218iod.7 for ; Thu, 16 Dec 2021 08:05:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=/pPKkXtT6Xrl9aqdgr4UGNl+ZJEtLSBkw/CIGk0Ps8Y=; b=hrAibA8VCiRbTVdDg+0x+InGlOJ+7hx7X3m+HVrRE6NeGaojnjD2KfBEJAt57Bx4kM ACupiwLU2vUmauKIDN301FUJJ6n1BgnD02odN8w3JnW7LCGe5nmxQDPO273GM4btJjUX V1FopdaIX6h0oB3RIpJX+b7FoyBH4NuoiYCF5pdu9KIJKIsQAk4iCep/Q66gGjd76o2a UIihO0OWoyCB2n2zPJ1YKWbBZhvMd420Jj3btrYZtg9ZwebXjibml4Gj9S3+5e4tpSBT wpX/Q6ij0l9dTKlSmI1nrvWocgsVnUXDiKwRHT32LoOmXssog1YLnFfkefG6El7MMS0Q RzXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=/pPKkXtT6Xrl9aqdgr4UGNl+ZJEtLSBkw/CIGk0Ps8Y=; b=gdlb5CG1cT0Z52+RPu43PxcG0X8D971Bi789nhPwm3zsQyA6q7i0FUqm661q3fiNwU /o4HjNuOH5hdERHBJzIL1HG9xOJTw8fbIB/l4xwv8/FxuqnDaPdNsVL8zlKrAu/ADCx7 C4w3Zhwikhjukxi1uBFXq0POqIAMQGHKvJjyc7IXlkUxpmsYbpTM/au7oZLuapVd9GXv YkioKq7ha9kVjc1fX4aYVxKuWCMs3H0JKhV51DOfjhZWL8sWd3n7komJm+SQFVNIouHb IMywbk+LDHd1deQrUMlutah94J4eAvswGDwbG9ia5NqTSdK+fqnVuEWobTnHUxFubTSu RcNQ== X-Gm-Message-State: AOAM533icke6isVXA/J/c4dKFiKyRAKLVQ5K7ONOL9PynDq7+zhnmsqy CuM0Cwi+LYSgtIbRY0JiT1BiutrztFgtUQ== X-Google-Smtp-Source: ABdhPJyZvGZ7Csc3Ozp6Tn4H9lRpoYb6zejMLBe6rUw9wqFXCf+CxyyNi5MRqbS6MX2EEwjVvOZdiQ== X-Received: by 2002:a05:6638:2055:: with SMTP id t21mr10015876jaj.90.1639670741326; Thu, 16 Dec 2021 08:05:41 -0800 (PST) Received: from x1.localdomain ([207.135.234.126]) by smtp.gmail.com with ESMTPSA id s9sm3237155ild.14.2021.12.16.08.05.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 16 Dec 2021 08:05:40 -0800 (PST) From: Jens Axboe To: io-uring@vger.kernel.org, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org Cc: Jens Axboe , Christoph Hellwig Subject: [PATCH 1/4] block: add mq_ops->queue_rqs hook Date: Thu, 16 Dec 2021 09:05:34 -0700 Message-Id: <20211216160537.73236-2-axboe@kernel.dk> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211216160537.73236-1-axboe@kernel.dk> References: <20211216160537.73236-1-axboe@kernel.dk> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org If we have a list of requests in our plug list, send it to the driver in one go, if possible. The driver must set mq_ops->queue_rqs() to support this, if not the usual one-by-one path is used. Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-mq.c | 26 +++++++++++++++++++++++--- include/linux/blk-mq.h | 8 ++++++++ 2 files changed, 31 insertions(+), 3 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 75154cc788db..51991232824a 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2553,6 +2553,7 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) { struct blk_mq_hw_ctx *this_hctx; struct blk_mq_ctx *this_ctx; + struct request *rq; unsigned int depth; LIST_HEAD(list); @@ -2561,7 +2562,28 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) plug->rq_count = 0; if (!plug->multiple_queues && !plug->has_elevator && !from_schedule) { - struct request_queue *q = rq_list_peek(&plug->mq_list)->q; + struct request_queue *q; + + rq = rq_list_peek(&plug->mq_list); + q = rq->q; + + /* + * Peek first request and see if we have a ->queue_rqs() hook. + * If we do, we can dispatch the whole plug list in one go. We + * already know at this point that all requests belong to the + * same queue, caller must ensure that's the case. + * + * Since we pass off the full list to the driver at this point, + * we do not increment the active request count for the queue. + * Bypass shared tags for now because of that. + */ + if (q->mq_ops->queue_rqs && + !(rq->mq_hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) { + blk_mq_run_dispatch_ops(q, + q->mq_ops->queue_rqs(&plug->mq_list)); + if (rq_list_empty(plug->mq_list)) + return; + } blk_mq_run_dispatch_ops(q, blk_mq_plug_issue_direct(plug, false)); @@ -2573,8 +2595,6 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule) this_ctx = NULL; depth = 0; do { - struct request *rq; - rq = rq_list_pop(&plug->mq_list); if (!this_hctx) { diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index 772f8f921526..550996cf419c 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -492,6 +492,14 @@ struct blk_mq_ops { */ void (*commit_rqs)(struct blk_mq_hw_ctx *); + /** + * @queue_rqs: Queue a list of new requests. Driver is guaranteed + * that each request belongs to the same queue. If the driver doesn't + * empty the @rqlist completely, then the rest will be queued + * individually by the block layer upon return. + */ + void (*queue_rqs)(struct request **rqlist); + /** * @get_budget: Reserve budget before queue request, once .queue_rq is * run, it is driver's responsibility to release the