From patchwork Mon Mar 29 15:26:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 12170363 X-Patchwork-Delegate: snitzer@redhat.com 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=-16.0 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=ham 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 E785EC433DB for ; Mon, 29 Mar 2021 15:28:11 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 96401617ED for ; Mon, 29 Mar 2021 15:28:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 96401617ED Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=dm-devel-bounces@redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617031690; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=TFggn6ky2dsoUjQNYEbmiSccmMhPmEte+zlj04fIIqI=; b=H5xnxC1pChOODLcDfUBWBnzYRb+w64tx+dTVy7J8UX6A58c8C49DmWM9NTZHbiVObDUs+M UvZrn9pU9OIoYbpYiVkrJSgzLZwwuHZ2e3ABo/ZNryye/9tl1U7PjqeXpCUSvw8XG41paD 83makoiNSvm8r4z8G2cA06pAzbX1CoM= 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-482-asJd-JKzPWG0VI4kb37GPg-1; Mon, 29 Mar 2021 11:28:07 -0400 X-MC-Unique: asJd-JKzPWG0VI4kb37GPg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 46A75881283; Mon, 29 Mar 2021 15:28:03 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1A4325D9F0; Mon, 29 Mar 2021 15:28:03 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id B338E180B451; Mon, 29 Mar 2021 15:28:02 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 12TFS1hm019520 for ; Mon, 29 Mar 2021 11:28:01 -0400 Received: by smtp.corp.redhat.com (Postfix) id 1778F5C582; Mon, 29 Mar 2021 15:28:01 +0000 (UTC) Received: from localhost (ovpn-12-50.pek2.redhat.com [10.72.12.50]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5A8225C5DF; Mon, 29 Mar 2021 15:28:00 +0000 (UTC) From: Ming Lei To: Jens Axboe Date: Mon, 29 Mar 2021 23:26:19 +0800 Message-Id: <20210329152622.173035-10-ming.lei@redhat.com> In-Reply-To: <20210329152622.173035-1-ming.lei@redhat.com> References: <20210329152622.173035-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-loop: dm-devel@redhat.com Cc: Mike Snitzer , Ming Lei , linux-block@vger.kernel.org, dm-devel@redhat.com, Jeffle Xu Subject: [dm-devel] [PATCH V4 09/12] blk-mq: limit hw queues to be polled in each blk_poll() X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Limit at most 8 queues are polled in each blk_pull(), avoid to add extra latency when queue depth is high. Signed-off-by: Ming Lei Reviewed-by: Jeffle Xu --- block/blk-mq.c | 73 ++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 53 insertions(+), 20 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index b65f2c170fb0..414f5d99d9de 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3865,32 +3865,31 @@ static inline int blk_mq_poll_hctx(struct request_queue *q, return ret; } -static int blk_mq_poll_io(struct bio *bio) +#define POLL_HCTX_MAX_CNT 8 + +static bool blk_add_unique_hctx(struct blk_mq_hw_ctx **data, int *cnt, + struct blk_mq_hw_ctx *hctx) { - struct request_queue *q = bio->bi_bdev->bd_disk->queue; - blk_qc_t cookie = bio_get_private_data(bio); - int ret = 0; + 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; @@ -3898,11 +3897,29 @@ 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; + cookie = bio_get_private_data(bio); + if (!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; @@ -3927,6 +3944,22 @@ 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; }