From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04F2CC43600 for ; Thu, 1 Apr 2021 02:22:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E80DA610C7 for ; Thu, 1 Apr 2021 02:22:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233102AbhDACWL (ORCPT ); Wed, 31 Mar 2021 22:22:11 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:36086 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233155AbhDACVt (ORCPT ); Wed, 31 Mar 2021 22:21:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617243708; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4PtUUiOR+GA8RordYFGfCjb74c0aCLBg8hc9ijEhfWk=; b=JaX/abCVcK1CMnRyqThY5TjekJUxk/Oh1PUUVzoAk9fxojCFHo+EX0Qp4igL/aW7lPHGor W4zv9Cxu5SRq+sVNywG1tfqmzg57HAGjYAjoS/8dbEnAE8E0y8ih0KjLQGIF4E1n5RBfWH 9SpFPrziC1DNUHSQb+tYVxFlqW1+wLI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-74--Z-BmyiWMJquXcPllKv-fw-1; Wed, 31 Mar 2021 22:21:46 -0400 X-MC-Unique: -Z-BmyiWMJquXcPllKv-fw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D16871084C83; Thu, 1 Apr 2021 02:21:45 +0000 (UTC) Received: from localhost (ovpn-12-93.pek2.redhat.com [10.72.12.93]) by smtp.corp.redhat.com (Postfix) with ESMTP id C0F795D720; Thu, 1 Apr 2021 02:21:38 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Jeffle Xu , Mike Snitzer , dm-devel@redhat.com, Hannes Reinecke , Ming Lei Subject: [PATCH V5 09/12] blk-mq: limit hw queues to be polled in each blk_poll() Date: Thu, 1 Apr 2021 10:19:24 +0800 Message-Id: <20210401021927.343727-10-ming.lei@redhat.com> In-Reply-To: <20210401021927.343727-1-ming.lei@redhat.com> References: <20210401021927.343727-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Limit at most 8 queues are polled in each blk_pull(), avoid to add extra latency when queue depth is high. Reviewed-by: Jeffle Xu Signed-off-by: Ming Lei --- block/blk-mq.c | 79 +++++++++++++++++++++++++++++++++++--------------- 1 file changed, 55 insertions(+), 24 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 20bfc8c2d02e..e2701d502e51 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3865,36 +3865,31 @@ static inline int blk_mq_poll_hctx(struct request_queue *q, return ret; } -static int blk_mq_poll_io(struct bio *bio) -{ - struct request_queue *q = bio->bi_bdev->bd_disk->queue; - blk_qc_t cookie = bio_get_private_data(bio); - int ret = 0; +#define POLL_HCTX_MAX_CNT 8 - /* wait until the bio is submitted really */ - if (!blk_qc_t_ready(cookie)) - return 0; +static bool blk_add_unique_hctx(struct blk_mq_hw_ctx **data, int *cnt, + struct blk_mq_hw_ctx *hctx) +{ + int i; - if (!bio_flagged(bio, BIO_DONE) && blk_qc_t_valid(cookie)) { - struct blk_mq_hw_ctx *hctx = - q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; + for (i = 0; i < *cnt; i++) { + if (data[i] == hctx) + goto exit; + } - ret += blk_mq_poll_hctx(q, hctx); + if (i < POLL_HCTX_MAX_CNT) { + data[i] = hctx; + (*cnt)++; } - return ret; + exit: + return *cnt == POLL_HCTX_MAX_CNT; } -static int blk_bio_poll_and_end_io(struct bio_grp_list *grps) +static void blk_build_poll_queues(struct bio_grp_list *grps, + struct blk_mq_hw_ctx **data, int *cnt) { - int ret = 0; int i; - /* - * Poll hw queue first. - * - * TODO: limit max poll times and make sure to not poll same - * hw queue one more time. - */ for (i = 0; i < grps->nr_grps; i++) { struct bio_grp_list_data *grp = &grps->head[i]; struct bio *bio; @@ -3902,11 +3897,31 @@ static int blk_bio_poll_and_end_io(struct bio_grp_list *grps) if (bio_grp_list_grp_empty(grp)) continue; - for (bio = grp->list.head; bio; bio = bio->bi_poll) - ret += blk_mq_poll_io(bio); + for (bio = grp->list.head; bio; bio = bio->bi_poll) { + blk_qc_t cookie; + struct blk_mq_hw_ctx *hctx; + struct request_queue *q; + + if (bio_flagged(bio, BIO_DONE)) + continue; + + /* wait until the bio is submitted really */ + cookie = bio_get_private_data(bio); + if (!blk_qc_t_ready(cookie) || !blk_qc_t_valid(cookie)) + continue; + + q = bio->bi_bdev->bd_disk->queue; + hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)]; + if (blk_add_unique_hctx(data, cnt, hctx)) + return; + } } +} + +static void blk_bio_poll_reap_ios(struct bio_grp_list *grps) +{ + int i; - /* reap bios */ for (i = 0; i < grps->nr_grps; i++) { struct bio_grp_list_data *grp = &grps->head[i]; struct bio *bio; @@ -3931,6 +3946,22 @@ static int blk_bio_poll_and_end_io(struct bio_grp_list *grps) } __bio_grp_list_merge(&grp->list, &bl); } +} + +static int blk_bio_poll_and_end_io(struct bio_grp_list *grps) +{ + int ret = 0; + int i; + struct blk_mq_hw_ctx *hctx[POLL_HCTX_MAX_CNT]; + int cnt = 0; + + blk_build_poll_queues(grps, hctx, &cnt); + + for (i = 0; i < cnt; i++) + ret += blk_mq_poll_hctx(hctx[i]->queue, hctx[i]); + + blk_bio_poll_reap_ios(grps); + return ret; } -- 2.29.2