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=-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=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 CCCC9C433E9 for ; Tue, 16 Mar 2021 03:19:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ABF156502E for ; Tue, 16 Mar 2021 03:19:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234773AbhCPDS5 (ORCPT ); Mon, 15 Mar 2021 23:18:57 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:34013 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231309AbhCPDS0 (ORCPT ); Mon, 15 Mar 2021 23:18:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615864705; 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=v2A/PMV03yGjSXb6zLcTex0eodeOpfhdbFj6ScnnbhQ=; b=UCrAm5Ywj8YNmxbOBv2hbPYexWvsRXiWIHXJDpjgilvxy0Tcm8LilfJ2aEno4ldED6yx95 v7GVN4GeKM3scTFUpfJ9dKoAN2HH6sIGoYyr5x8mNkulRQtOtZbBKj1/5mGL1XO3PeIlAl etmEslZHc6j+KrgTZx0DBVhNBSeisuM= 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-592-0f0lJ0WBOWK-84C9rIT1fw-1; Mon, 15 Mar 2021 23:18:23 -0400 X-MC-Unique: 0f0lJ0WBOWK-84C9rIT1fw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3183680006E; Tue, 16 Mar 2021 03:18:22 +0000 (UTC) Received: from localhost (ovpn-12-86.pek2.redhat.com [10.72.12.86]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8401E1B472; Tue, 16 Mar 2021 03:18:12 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Jeffle Xu , Mike Snitzer , dm-devel@redhat.com, Ming Lei Subject: [RFC PATCH 05/11] block: add req flag of REQ_TAG Date: Tue, 16 Mar 2021 11:15:17 +0800 Message-Id: <20210316031523.864506-6-ming.lei@redhat.com> In-Reply-To: <20210316031523.864506-1-ming.lei@redhat.com> References: <20210316031523.864506-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Add one req flag REQ_TAG which will be used in the following patch for supporting bio based IO polling. Exactly this flag can help us to do: 1) request flag is cloned in bio_fast_clone(), so if we mark one FS bio as REQ_TAG, all bios cloned from this FS bio will be marked as REQ_TAG. 2)create per-task io polling context if the bio based queue supports polling and the submitted bio is HIPRI. This per-task io polling context will be created during submit_bio() before marking this HIPRI bio as REQ_TAG. Then we can avoid to create such io polling context if one cloned bio with REQ_TAG is submitted from another kernel context. 3) for supporting bio based io polling, we need to poll IOs from all underlying queues of bio device/driver, this way help us to recognize which IOs need to polled in bio based style, which will be implemented in next patch. Signed-off-by: Ming Lei --- block/blk-core.c | 29 +++++++++++++++++++++++++++-- include/linux/blk_types.h | 4 ++++ 2 files changed, 31 insertions(+), 2 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 7c7b0dba4f5c..a082bbc856fb 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -828,11 +828,30 @@ void bio_poll_ctx_alloc(struct io_context *ioc) static inline void blk_bio_poll_preprocess(struct request_queue *q, struct bio *bio) { + bool mq; + if (!(bio->bi_opf & REQ_HIPRI)) return; - if (!blk_queue_poll(q) || (!queue_is_mq(q) && !blk_get_bio_poll_ctx())) + /* + * Can't support bio based IO poll without per-task poll queue + * + * Now we have created per-task io poll context, and mark this + * bio as REQ_TAG, so: 1) if any cloned bio from this bio is + * submitted from another kernel context, we won't create bio + * poll context for it, so that bio will be completed by IRQ; + * 2) If such bio is submitted from current context, we will + * complete it via blk_poll(); 3) If driver knows that one + * underlying bio allocated from driver is for FS bio, meantime + * it is submitted in current context, driver can mark such bio + * as REQ_TAG manually, so the bio can be completed via blk_poll + * too. + */ + mq = queue_is_mq(q); + if (!blk_queue_poll(q) || (!mq && !blk_get_bio_poll_ctx())) bio->bi_opf &= ~REQ_HIPRI; + else if (!mq) + bio->bi_opf |= REQ_TAG; } static noinline_for_stack bool submit_bio_checks(struct bio *bio) @@ -881,9 +900,15 @@ static noinline_for_stack bool submit_bio_checks(struct bio *bio) /* * Created per-task io poll queue if we supports bio polling - * and it is one HIPRI bio. + * and it is one HIPRI bio, and this HIPRI bio has to be from + * FS. If REQ_TAG isn't set for HIPRI bio, we think it originated + * from FS. + * + * Driver may allocated bio by itself and REQ_TAG is set, but they + * won't be marked as HIPRI. */ blk_create_io_context(q, blk_queue_support_bio_poll(q) && + !(bio->bi_opf & REQ_TAG) && (bio->bi_opf & REQ_HIPRI)); blk_bio_poll_preprocess(q, bio); diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index db026b6ec15a..a1bcade4bcc3 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -394,6 +394,9 @@ enum req_flag_bits { __REQ_HIPRI, + /* for marking IOs originated from same FS bio in same context */ + __REQ_TAG, + /* for driver use */ __REQ_DRV, __REQ_SWAP, /* swapping request. */ @@ -418,6 +421,7 @@ enum req_flag_bits { #define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP) #define REQ_HIPRI (1ULL << __REQ_HIPRI) +#define REQ_TAG (1ULL << __REQ_TAG) #define REQ_DRV (1ULL << __REQ_DRV) #define REQ_SWAP (1ULL << __REQ_SWAP) -- 2.29.2