Commit bcbee854 authored by Alexey Marchuk's avatar Alexey Marchuk Committed by Jim Harris
Browse files

nvme/tcp: Report correct max sge 



NVME TCP driver supports up to 16 sge elements
while only 1 sge is reported - that leads to
unnecessary requests split which degrades perf.
Also pass correct iovcnt to nvme_tcp_build_iovs -
it should be 32. Otherwise, pdu header consumes
1 iov and data is written partially.
Add a check that at least data_len bytes were
appended to the socket iovs and fail request
otherwise.

Signed-off-by: default avatarAlexey Marchuk <alexeymar@nvidia.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/17006

 (master)

(cherry picked from commit ada93334)
Change-Id: Ie83c807dd3fec2c7e7cbcda1e493d6fd74ebe599
Signed-off-by: default avatarKrzysztof Karas <krzysztof.karas@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/17699


Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarKonrad Sztyber <konrad.sztyber@intel.com>
parent a3351726

lib/nvme/nvme_tcp.c

+10 −10
Original line number Diff line number Diff line 
/*   SPDX-License-Identifier: BSD-3-Clause

 *   Copyright (C) 2018 Intel Corporation. All rights reserved.

 *   Copyright (c) 2020 Mellanox Technologies LTD. All rights reserved.

 *   Copyright (c) 2021, 2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved.

 *   Copyright (c) 2021-2023 NVIDIA CORPORATION & AFFILIATES. All rights reserved.

 */



/*
@@ -412,12 +412,18 @@ _tcp_write_pdu(struct nvme_tcp_pdu *pdu) 
	uint32_t mapped_length = 0;

	struct nvme_tcp_qpair *tqpair = pdu->qpair;



	pdu->sock_req.iovcnt = nvme_tcp_build_iovs(pdu->iov, NVME_TCP_MAX_SGL_DESCRIPTORS, pdu,

	pdu->sock_req.iovcnt = nvme_tcp_build_iovs(pdu->iov, SPDK_COUNTOF(pdu->iov), pdu,

			       (bool)tqpair->flags.host_hdgst_enable, (bool)tqpair->flags.host_ddgst_enable,

			       &mapped_length);

	TAILQ_INSERT_TAIL(&tqpair->send_queue, pdu, tailq);

	if (spdk_unlikely(mapped_length < pdu->data_len)) {

		SPDK_ERRLOG("could not map the whole %u bytes (mapped only %u bytes)\n", pdu->data_len,

			    mapped_length);

		_pdu_write_done(pdu, -EINVAL);

		return;

	}

	pdu->sock_req.cb_fn = _pdu_write_done;

	pdu->sock_req.cb_arg = pdu;

	TAILQ_INSERT_TAIL(&tqpair->send_queue, pdu, tailq);

	tqpair->stats->submitted_requests++;

	spdk_sock_writev_async(tqpair->sock, &pdu->sock_req);

}
@@ -2167,13 +2173,7 @@ nvme_tcp_ctrlr_get_max_xfer_size(struct spdk_nvme_ctrlr *ctrlr) 
static uint16_t

nvme_tcp_ctrlr_get_max_sges(struct spdk_nvme_ctrlr *ctrlr)

{

	/*

	 * We do not support >1 SGE in the initiator currently,

	 *  so we can only return 1 here.  Once that support is

	 *  added, this should return ctrlr->cdata.nvmf_specific.msdbd

	 *  instead.

	 */

	return 1;

	return NVME_TCP_MAX_SGL_DESCRIPTORS;

}



static int