From patchwork Wed Mar 24 12:19:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 12160931 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 6FCFDC433DB for ; Wed, 24 Mar 2021 12:21:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DA2361A05 for ; Wed, 24 Mar 2021 12:21:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231601AbhCXMU7 (ORCPT ); Wed, 24 Mar 2021 08:20:59 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:47765 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232702AbhCXMUg (ORCPT ); Wed, 24 Mar 2021 08:20:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616588435; 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=MYGc4BGrp2sB5b5YVOPh7B2xVfNN/UBEr+fKsyZ2etA=; b=Auxnz184yAfBiw2h83xcMfKyWGYb/Pdw/TZicObh88CR5EhCJovvE6FKp7dor2FJy1gQK1 WcUApjwY+seKx15HT7dVu+g7I+oRqbqsBVsFSV3D6ezdcIAFwsiffc/mOh/TUojay867rL o4K21Mc4CQzl24A0qATlgxWYqcxGLJo= 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-422-7Z-1OKouOLWQyz5QPGgmqw-1; Wed, 24 Mar 2021 08:20:33 -0400 X-MC-Unique: 7Z-1OKouOLWQyz5QPGgmqw-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 F28D381621; Wed, 24 Mar 2021 12:20:32 +0000 (UTC) Received: from localhost (ovpn-13-127.pek2.redhat.com [10.72.13.127]) by smtp.corp.redhat.com (Postfix) with ESMTP id A42136A032; Wed, 24 Mar 2021 12:20:25 +0000 (UTC) From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Jeffle Xu , Mike Snitzer , dm-devel@redhat.com, Ming Lei Subject: [PATCH V3 05/13] block: add req flag of REQ_POLL_CTX Date: Wed, 24 Mar 2021 20:19:19 +0800 Message-Id: <20210324121927.362525-6-ming.lei@redhat.com> In-Reply-To: <20210324121927.362525-1-ming.lei@redhat.com> References: <20210324121927.362525-1-ming.lei@redhat.com> MIME-Version: 1.0 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_POLL_CTX 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_POLL_CTX, all bios cloned from this FS bio will be marked as REQ_POLL_CTX too. 2) create per-task io polling context if the bio based queue supports polling and the submitted bio is HIPRI. Per-task io poll context will be created during submit_bio() before marking this HIPRI bio as REQ_POLL_CTX. Then we can avoid to create such io polling context if one cloned bio with REQ_POLL_CTX is submitted from another kernel context. 3) for supporting bio based io polling, we need to poll IOs from all underlying queues of the bio device, this way help us to recognize which IO needs to polled in bio based style, which will be applied in following patch. Signed-off-by: Ming Lei Reviewed-by: Jeffle Xu --- block/blk-core.c | 25 ++++++++++++++++++++++++- include/linux/blk_types.h | 4 ++++ 2 files changed, 28 insertions(+), 1 deletion(-) diff --git a/block/blk-core.c b/block/blk-core.c index 4671bbf31fd3..eb07d61cfdc2 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -840,11 +840,30 @@ static inline bool blk_queue_support_bio_poll(struct request_queue *q) 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 polling without per-task poll ctx + * + * We have created per-task io poll context, and mark this + * bio as REQ_POLL_CTX, so: 1) if any cloned bio from this bio is + * submitted from another kernel context, we won't create bio + * poll context for it, and that bio can 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_HIPRI & REQ_POLL_CTX 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_POLL_CTX; } static noinline_for_stack bool submit_bio_checks(struct bio *bio) @@ -894,8 +913,12 @@ static noinline_for_stack bool submit_bio_checks(struct bio *bio) /* * Create per-task io poll ctx if bio polling supported and HIPRI * set. + * + * If REQ_POLL_CTX isn't set for this HIPRI bio, we think it originated + * from FS and allocate io polling context. */ blk_create_io_context(q, blk_queue_support_bio_poll(q) && + !(bio->bi_opf & REQ_POLL_CTX) && (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..99160d588c2d 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_POLL_CTX, + /* 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_POLL_CTX (1ULL << __REQ_POLL_CTX) #define REQ_DRV (1ULL << __REQ_DRV) #define REQ_SWAP (1ULL << __REQ_SWAP)