From nobody Tue Dec 2 02:04:05 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 21FAA2D130B for ; Fri, 21 Nov 2025 02:00:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763690425; cv=none; b=V69Unu2PubJXXbwgBU2jEY4F88pMQNx2+v4lUK53933U0qnWUPbznU9/tIH/qoNMXRlwVRnXLFLGw/edoqaslm5hY/G5wjsHohGPSsrrobNpY01Fk8e9luA0RwhpwwbtQVOn/8NYGP9M+BfSkOmOKAf+MCEyzK+5Cdu8F6yU9ws= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763690425; c=relaxed/simple; bh=lZFQkkcIQFUAUsfrreKNnoPIzb8RfsdfF4lwfsW1fR8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TT0q9+GoCN+FOwDggBo41LlB5F1Z1pOCpA/9YfAXQ2KZNp8W88zIRNuriZ0H082GS3+8EP9SvC///G/64EffP/SrXkhJTaiQbZTFtNFzM/+5LPRYdArWCGU+fUY3sBef/3BmBWox30HDMqWD0p8olbJdNrgIp3kU2F0dy4gW2e0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=eWlF22tS; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="eWlF22tS" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1763690423; 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=lYUBO2QVHXZ0L0CaVikfzhTp2/fJbjkXi40POyUJvkA=; b=eWlF22tSVkc4q0wWWtOYb74gJQxeQy3a/QHZskK9mgVsPAEmwCQhJqZD0jIgcx0AdrIiwC R3mKbEDlVFFueKultvsrBuUqJDRtPNhbynuMejGSIfFAtOYwzy1F5BoQl/9819xkwxgMx4 4VTGwdherQ4/syjwf1uMxSmyIMblgjA= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-481-s7UGkC_MMXKZVHrmbcZyQw-1; Thu, 20 Nov 2025 21:00:18 -0500 X-MC-Unique: s7UGkC_MMXKZVHrmbcZyQw-1 X-Mimecast-MFC-AGG-ID: s7UGkC_MMXKZVHrmbcZyQw_1763690417 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id DF583180047F; Fri, 21 Nov 2025 02:00:16 +0000 (UTC) Received: from localhost (unknown [10.72.116.211]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 0733D1956045; Fri, 21 Nov 2025 02:00:15 +0000 (UTC) From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org Cc: Caleb Sander Mateos , Uday Shankar , Stefani Seibold , Andrew Morton , linux-kernel@vger.kernel.org, Ming Lei Subject: [PATCH V4 18/27] ublk: implement batch request completion via blk_mq_end_request_batch() Date: Fri, 21 Nov 2025 09:58:40 +0800 Message-ID: <20251121015851.3672073-19-ming.lei@redhat.com> In-Reply-To: <20251121015851.3672073-1-ming.lei@redhat.com> References: <20251121015851.3672073-1-ming.lei@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Content-Type: text/plain; charset="utf-8" Reduce overhead when completing multiple requests in batch I/O mode by accumulating them in an io_comp_batch structure and completing them together via blk_mq_end_request_batch(). This minimizes per-request completion overhead and improves performance for high IOPS workloads. The implementation adds an io_comp_batch pointer to struct ublk_io and initializes it in __ublk_fetch(). For batch I/O, the pointer is set to the batch structure in ublk_batch_commit_io(). The __ublk_complete_rq() function uses io->iob to call blk_mq_add_to_batch() for batch mode. After processing all batch I/Os, the completion callback is invoked in ublk_handle_batch_commit_cmd() to complete all accumulated requests efficiently. So far just covers direct completion. For deferred completion(zero copy, auto buffer reg), ublk_io_release() is often delayed in freeing buffer consumer io_uring request's code path, so this patch often doesn't work, also it is hard to pass the per-task 'struct io_comp_batch' for deferred completion. Signed-off-by: Ming Lei Reviewed-by: Caleb Sander Mateos --- drivers/block/ublk_drv.c | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 90cd1863bc83..a5606c7111a4 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -130,6 +130,7 @@ struct ublk_batch_io_data { struct io_uring_cmd *cmd; struct ublk_batch_io header; unsigned int issue_flags; + struct io_comp_batch *iob; }; =20 /* @@ -642,7 +643,12 @@ static blk_status_t ublk_setup_iod_zoned(struct ublk_q= ueue *ubq, #endif =20 static inline void __ublk_complete_rq(struct request *req, struct ublk_io = *io, - bool need_map); + bool need_map, struct io_comp_batch *iob); + +static void ublk_complete_batch(struct io_comp_batch *iob) +{ + blk_mq_end_request_batch(iob); +} =20 static dev_t ublk_chr_devt; static const struct class ublk_chr_class =3D { @@ -912,7 +918,7 @@ static inline void ublk_put_req_ref(struct ublk_io *io,= struct request *req) return; =20 /* ublk_need_map_io() and ublk_need_req_ref() are mutually exclusive */ - __ublk_complete_rq(req, io, false); + __ublk_complete_rq(req, io, false, NULL); } =20 static inline bool ublk_sub_req_ref(struct ublk_io *io) @@ -1251,7 +1257,7 @@ static inline struct ublk_uring_cmd_pdu *ublk_get_uri= ng_cmd_pdu( =20 /* todo: handle partial completion */ static inline void __ublk_complete_rq(struct request *req, struct ublk_io = *io, - bool need_map) + bool need_map, struct io_comp_batch *iob) { unsigned int unmapped_bytes; blk_status_t res =3D BLK_STS_OK; @@ -1288,8 +1294,11 @@ static inline void __ublk_complete_rq(struct request= *req, struct ublk_io *io, =20 if (blk_update_request(req, BLK_STS_OK, io->res)) blk_mq_requeue_request(req, true); - else if (likely(!blk_should_fake_timeout(req->q))) + else if (likely(!blk_should_fake_timeout(req->q))) { + if (blk_mq_add_to_batch(req, iob, false, ublk_complete_batch)) + return; __blk_mq_end_request(req, BLK_STS_OK); + } =20 return; exit: @@ -2249,7 +2258,7 @@ static void __ublk_fail_req(struct ublk_device *ub, s= truct ublk_io *io, blk_mq_requeue_request(req, false); else { io->res =3D -EIO; - __ublk_complete_rq(req, io, ublk_dev_need_map_io(ub)); + __ublk_complete_rq(req, io, ublk_dev_need_map_io(ub), NULL); } } =20 @@ -2986,7 +2995,7 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cm= d *cmd, if (req_op(req) =3D=3D REQ_OP_ZONE_APPEND) req->__sector =3D addr; if (compl) - __ublk_complete_rq(req, io, ublk_dev_need_map_io(ub)); + __ublk_complete_rq(req, io, ublk_dev_need_map_io(ub), NULL); =20 if (ret) goto out; @@ -3321,11 +3330,11 @@ static int ublk_batch_commit_io(struct ublk_queue *= ubq, if (req_op(req) =3D=3D REQ_OP_ZONE_APPEND) req->__sector =3D ublk_batch_zone_lba(uc, elem); if (compl) - __ublk_complete_rq(req, io, ublk_dev_need_map_io(data->ub)); + __ublk_complete_rq(req, io, ublk_dev_need_map_io(data->ub), data->iob); return 0; } =20 -static int ublk_handle_batch_commit_cmd(const struct ublk_batch_io_data *d= ata) +static int ublk_handle_batch_commit_cmd(struct ublk_batch_io_data *data) { const struct ublk_batch_io *uc =3D &data->header; struct io_uring_cmd *cmd =3D data->cmd; @@ -3334,10 +3343,15 @@ static int ublk_handle_batch_commit_cmd(const struc= t ublk_batch_io_data *data) .total =3D uc->nr_elem * uc->elem_bytes, .elem_bytes =3D uc->elem_bytes, }; + DEFINE_IO_COMP_BATCH(iob); int ret; =20 + data->iob =3D &iob; ret =3D ublk_walk_cmd_buf(&iter, data, ublk_batch_commit_io); =20 + if (iob.complete) + iob.complete(&iob); + return iter.done =3D=3D 0 ? ret : iter.done; } =20 --=20 2.47.0