From patchwork Mon May 15 14:46:00 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 13241669 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 6BD74C7EE2C for ; Mon, 15 May 2023 14:49:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235256AbjEOOtL (ORCPT ); Mon, 15 May 2023 10:49:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234849AbjEOOtF (ORCPT ); Mon, 15 May 2023 10:49:05 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED3F310E7 for ; Mon, 15 May 2023 07:48:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684162092; 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=BezdMmFur1+mPESSTDe8haOWPaj4BeqZewTpb/LMRkE=; b=BzEcBtZAz6XuSCRLG/ZUVgdUBE7QpylBRHsovZmysWY9+JvXHEp+yUPpLE2cMh3Wnczc0u gCtZAmGD+TK5OHW4OUSBifT3d/Das48YSmjQOmNL1kRK83yXWGpvk8vbGd+MzKUiX/h3JC rrRFJNxeHf/xBbenqd1IF7yTwtkI0UE= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-324-olr1CMTLOBm86LuZ1YXqLA-1; Mon, 15 May 2023 10:48:06 -0400 X-MC-Unique: olr1CMTLOBm86LuZ1YXqLA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 5DDC61C0513D; Mon, 15 May 2023 14:48:06 +0000 (UTC) Received: from localhost (ovpn-8-26.pek2.redhat.com [10.72.8.26]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5A69B1121314; Mon, 15 May 2023 14:48:04 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Ming Lei , Guangwu Zhang , Yu Kuai Subject: [PATCH V2 1/2] blk-mq: don't queue plugged passthrough requests into scheduler Date: Mon, 15 May 2023 22:46:00 +0800 Message-Id: <20230515144601.52811-2-ming.lei@redhat.com> In-Reply-To: <20230515144601.52811-1-ming.lei@redhat.com> References: <20230515144601.52811-1-ming.lei@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Passthrough(pt) request shouldn't be queued to scheduler, especially some schedulers(such as bfq) supposes that req->bio is always available, then blk-cgroup can be retrieved via bio. We never let passthrough request cross scheduler before commit 1c2d2fff6dc0 ("block: wire-up support for passthrough plugging"). Fix this issue by queuing pt request from plug list to hctx->dispatch directly. Reported-by: Guangwu Zhang Closes: https://lore.kernel.org/linux-block/CAGS2=YosaYaUTEMU3uaf+y=8MqSrhL7sYsJn8EwbaM=76p_4Qg@mail.gmail.com/ Investigated-by: Yu Kuai Fixes: 1c2d2fff6dc0 ("block: wire-up support for passthrough plugging") Signed-off-by: Ming Lei --- block/blk-mq.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index f6dad0886a2f..b4aaf42f1125 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2711,6 +2711,7 @@ static void blk_mq_dispatch_plug_list(struct blk_plug *plug, bool from_sched) struct request *requeue_list = NULL; struct request **requeue_lastp = &requeue_list; unsigned int depth = 0; + bool pt = false; LIST_HEAD(list); do { @@ -2719,7 +2720,14 @@ static void blk_mq_dispatch_plug_list(struct blk_plug *plug, bool from_sched) if (!this_hctx) { this_hctx = rq->mq_hctx; this_ctx = rq->mq_ctx; - } else if (this_hctx != rq->mq_hctx || this_ctx != rq->mq_ctx) { + pt = blk_rq_is_passthrough(rq); + } else if (this_hctx != rq->mq_hctx || this_ctx != rq->mq_ctx || + pt != blk_rq_is_passthrough(rq)) { + /* + * Both passthrough and flush request don't belong to + * scheduler, but flush request won't be added to plug + * list, so needn't handle here. + */ rq_list_add_tail(&requeue_lastp, rq); continue; } @@ -2731,7 +2739,13 @@ static void blk_mq_dispatch_plug_list(struct blk_plug *plug, bool from_sched) trace_block_unplug(this_hctx->queue, depth, !from_sched); percpu_ref_get(&this_hctx->queue->q_usage_counter); - if (this_hctx->queue->elevator) { + /* passthrough requests don't belong to scheduler */ + if (pt) { + spin_lock(&this_hctx->lock); + list_splice_tail_init(&list, &this_hctx->dispatch); + spin_unlock(&this_hctx->lock); + blk_mq_run_hw_queue(this_hctx, from_sched); + } else if (this_hctx->queue->elevator) { this_hctx->queue->elevator->type->ops.insert_requests(this_hctx, &list, 0); blk_mq_run_hw_queue(this_hctx, from_sched);