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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0185C04A68 for ; Thu, 28 Jul 2022 15:35:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229543AbiG1Pfr (ORCPT ); Thu, 28 Jul 2022 11:35:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229449AbiG1Pfq (ORCPT ); Thu, 28 Jul 2022 11:35:46 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id E95B61B7BC for ; Thu, 28 Jul 2022 08:35:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1659022545; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=co9k6FCRwybaqu2K2lkTGvTayTdtBDNtJFNeUOoFIFQ=; b=J19kn9uc4k8sXy3yqH85p6Exgkc8WrvsimSoA+GeMfHBu6HoR0dhwyfM37AkLKj2DDXYz9 Ryx0FHGqLrqaL2DYibav82cQmyosy8wRNccFEO+TBu62nTd1tL26jaxfjFWpZJX7SmOxDp c19yQUnlXY5wwuUIH74G+yTlNHxiwj4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-303-Bij5K36nO-m_xx_oWAYCcw-1; Thu, 28 Jul 2022 11:35:40 -0400 X-MC-Unique: Bij5K36nO-m_xx_oWAYCcw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 28B471019C8D; Thu, 28 Jul 2022 15:35:40 +0000 (UTC) Received: from T590 (ovpn-8-26.pek2.redhat.com [10.72.8.26]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2CD142026D64; Thu, 28 Jul 2022 15:35:35 +0000 (UTC) Date: Thu, 28 Jul 2022 23:35:31 +0800 From: Ming Lei To: Hannes Reinecke Cc: Christoph Hellwig , Jens Axboe , linux-block@vger.kernel.org, Damien Le Moal , Johannes Thumshirn Subject: Re: [PATCH 3/6] block: move ->bio_split to the gendisk Message-ID: References: <20220727162300.3089193-1-hch@lst.de> <20220727162300.3089193-4-hch@lst.de> <5323f3a1-14ac-eafb-3b5a-493fea2e86f5@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5323f3a1-14ac-eafb-3b5a-493fea2e86f5@suse.de> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Jul 28, 2022 at 10:07:14AM +0200, Hannes Reinecke wrote: > On 7/27/22 18:22, Christoph Hellwig wrote: > > Only non-passthrough requests are split by the block layer and use the > > ->bio_split bio_set. Move it from the request_queue to the gendisk. > > > > Signed-off-by: Christoph Hellwig > > Reviewed-by: Damien Le Moal > > Reviewed-by: Johannes Thumshirn > > --- > > block/blk-core.c | 9 +-------- > > block/blk-merge.c | 7 ++++--- > > block/blk-sysfs.c | 2 -- > > block/genhd.c | 8 +++++++- > > drivers/md/dm.c | 2 +- > > include/linux/blkdev.h | 3 ++- > > 6 files changed, 15 insertions(+), 16 deletions(-) > > > > diff --git a/block/blk-core.c b/block/blk-core.c > > index 123468b9d2e43..59f13d011949d 100644 > > --- a/block/blk-core.c > > +++ b/block/blk-core.c > > @@ -377,7 +377,6 @@ static void blk_timeout_work(struct work_struct *work) > > struct request_queue *blk_alloc_queue(int node_id, bool alloc_srcu) > > { > > struct request_queue *q; > > - int ret; > > q = kmem_cache_alloc_node(blk_get_queue_kmem_cache(alloc_srcu), > > GFP_KERNEL | __GFP_ZERO, node_id); > > @@ -396,13 +395,9 @@ struct request_queue *blk_alloc_queue(int node_id, bool alloc_srcu) > > if (q->id < 0) > > goto fail_srcu; > > - ret = bioset_init(&q->bio_split, BIO_POOL_SIZE, 0, 0); > > - if (ret) > > - goto fail_id; > > - > > q->stats = blk_alloc_queue_stats(); > > if (!q->stats) > > - goto fail_split; > > + goto fail_id; > > q->node = node_id; > > @@ -439,8 +434,6 @@ struct request_queue *blk_alloc_queue(int node_id, bool alloc_srcu) > > fail_stats: > > blk_free_queue_stats(q->stats); > > -fail_split: > > - bioset_exit(&q->bio_split); > > fail_id: > > ida_free(&blk_queue_ida, q->id); > > fail_srcu: > > diff --git a/block/blk-merge.c b/block/blk-merge.c > > index 6e29fb28584ef..30872a3537648 100644 > > --- a/block/blk-merge.c > > +++ b/block/blk-merge.c > > @@ -331,18 +331,19 @@ static struct bio *bio_split_rw(struct bio *bio, struct request_queue *q, > > struct bio *__bio_split_to_limits(struct bio *bio, struct request_queue *q, > > unsigned int *nr_segs) > > { > > + struct bio_set *bs = &bio->bi_bdev->bd_disk->bio_split; > > struct bio *split; > > What happens for nvme-multipath? > While I know that we shouldn't split on a path, experience shows that we > _will_ do it eventually. You mean contiguous bios should be mapped to one same path? If yes, at least the current block layer can't do that, here dm-mapth is same with nvme-mpath, since bio is always split first, and the split small bio can be mapped to other path. Thanks, Ming