From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 54989A00C4; Fri, 1 Jul 2022 12:28:51 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 804A6427F3; Fri, 1 Jul 2022 12:28:46 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mails.dpdk.org (Postfix) with ESMTP id C5E71427F3 for ; Fri, 1 Jul 2022 12:28:45 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A38CB143D; Fri, 1 Jul 2022 03:28:45 -0700 (PDT) Received: from net-arm-n1amp-02.shanghai.arm.com (net-arm-n1amp-02.shanghai.arm.com [10.169.210.136]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 9AEC53F66F; Fri, 1 Jul 2022 03:28:42 -0700 (PDT) From: Joyce Kong To: Jakub Grajciar Cc: dev@dpdk.org, nd@arm.com, Joyce Kong , Ruifeng Wang , =?UTF-8?q?Morten=20Br=C3=B8rup?= Subject: [PATCH v2 2/2] net/memif: add a Tx fast path Date: Fri, 1 Jul 2022 10:28:15 +0000 Message-Id: <20220701102815.1444223-3-joyce.kong@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220701102815.1444223-1-joyce.kong@arm.com> References: <20220517105109.1086090-1-joyce.kong@arm.com> <20220701102815.1444223-1-joyce.kong@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org For memif non-zero-copy mode, there is a branch to compare the mbuf and memif buffer size during memory copying. If all mbufs come from the same mempool, and memif buf size >= mbuf size, add a fast Tx memory copy path without the comparing branch and with mbuf bulk free, otherwise still run the original Tx path. The Tx fast path would not change memif's behavior of storing mbuf. The removal of the branch and bulk free lead to considerable performance uplift. Test with 1p1q on Ampere Altra AArch64 server, ---------------------------------------------- | buf size | memif >= mbuf | memif < mbuf | ---------------------------------------------- | non-zc gain | 13.35% | -0.77% | ---------------------------------------------- | zc gain | 17.15% | -0.47% | ---------------------------------------------- Test with 1p1q on Cascade Lake Xeon X86server, ---------------------------------------------- | buf size | memif >= mbuf | memif < mbuf | ---------------------------------------------- | non-zc gain | 10.10% | -0.29% | ---------------------------------------------- | zc gain | 8.87% | -0.99% | ---------------------------------------------- Signed-off-by: Joyce Kong Reviewed-by: Ruifeng Wang Acked-by: Morten Brørup --- drivers/net/memif/rte_eth_memif.c | 134 ++++++++++++++++++++---------- 1 file changed, 92 insertions(+), 42 deletions(-) diff --git a/drivers/net/memif/rte_eth_memif.c b/drivers/net/memif/rte_eth_memif.c index 24fc8b13fa..bafcfd5a7c 100644 --- a/drivers/net/memif/rte_eth_memif.c +++ b/drivers/net/memif/rte_eth_memif.c @@ -659,62 +659,112 @@ eth_memif_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts) n_free = __atomic_load_n(&ring->head, __ATOMIC_ACQUIRE) - slot; } - while (n_tx_pkts < nb_pkts && n_free) { - mbuf_head = *bufs++; - nb_segs = mbuf_head->nb_segs; - mbuf = mbuf_head; + uint8_t i; + struct rte_mbuf **buf_tmp = bufs; + mbuf_head = *buf_tmp++; + struct rte_mempool *mp = mbuf_head->pool; + + for (i = 1; i < nb_pkts; i++) { + mbuf_head = *buf_tmp++; + if (mbuf_head->pool != mp) + break; + } + + uint16_t mbuf_size = rte_pktmbuf_data_room_size(mp) - RTE_PKTMBUF_HEADROOM; + if (i == nb_pkts && pmd->cfg.pkt_buffer_size >= mbuf_size) { + buf_tmp = bufs; + while (n_tx_pkts < nb_pkts && n_free) { + mbuf_head = *bufs++; + nb_segs = mbuf_head->nb_segs; + mbuf = mbuf_head; - saved_slot = slot; - d0 = &ring->desc[slot & mask]; - dst_off = 0; - dst_len = (type == MEMIF_RING_C2S) ? - pmd->run.pkt_buffer_size : d0->length; + saved_slot = slot; -next_in_chain: - src_off = 0; - src_len = rte_pktmbuf_data_len(mbuf); +next_in_chain1: + d0 = &ring->desc[slot & mask]; + cp_len = rte_pktmbuf_data_len(mbuf); - while (src_len) { - if (dst_len == 0) { + rte_memcpy((uint8_t *)memif_get_buffer(proc_private, d0), + rte_pktmbuf_mtod(mbuf, void *), cp_len); + + d0->length = cp_len; + mq->n_bytes += cp_len; + slot++; + n_free--; + + if (--nb_segs > 0) { if (n_free) { - slot++; - n_free--; d0->flags |= MEMIF_DESC_FLAG_NEXT; - d0 = &ring->desc[slot & mask]; - dst_off = 0; - dst_len = (type == MEMIF_RING_C2S) ? - pmd->run.pkt_buffer_size : d0->length; - d0->flags = 0; + mbuf = mbuf->next; + goto next_in_chain1; } else { slot = saved_slot; - goto no_free_slots; + goto free_mbufs; } } - cp_len = RTE_MIN(dst_len, src_len); - rte_memcpy((uint8_t *)memif_get_buffer(proc_private, - d0) + dst_off, - rte_pktmbuf_mtod_offset(mbuf, void *, src_off), - cp_len); + n_tx_pkts++; + } +free_mbufs: + rte_pktmbuf_free_bulk(buf_tmp, n_tx_pkts); + } else { + while (n_tx_pkts < nb_pkts && n_free) { + mbuf_head = *bufs++; + nb_segs = mbuf_head->nb_segs; + mbuf = mbuf_head; - mq->n_bytes += cp_len; - src_off += cp_len; - dst_off += cp_len; - src_len -= cp_len; - dst_len -= cp_len; + saved_slot = slot; + d0 = &ring->desc[slot & mask]; + dst_off = 0; + dst_len = (type == MEMIF_RING_C2S) ? + pmd->run.pkt_buffer_size : d0->length; - d0->length = dst_off; - } +next_in_chain2: + src_off = 0; + src_len = rte_pktmbuf_data_len(mbuf); - if (--nb_segs > 0) { - mbuf = mbuf->next; - goto next_in_chain; - } + while (src_len) { + if (dst_len == 0) { + if (n_free) { + slot++; + n_free--; + d0->flags |= MEMIF_DESC_FLAG_NEXT; + d0 = &ring->desc[slot & mask]; + dst_off = 0; + dst_len = (type == MEMIF_RING_C2S) ? + pmd->run.pkt_buffer_size : d0->length; + d0->flags = 0; + } else { + slot = saved_slot; + goto no_free_slots; + } + } + cp_len = RTE_MIN(dst_len, src_len); - n_tx_pkts++; - slot++; - n_free--; - rte_pktmbuf_free(mbuf_head); + rte_memcpy((uint8_t *)memif_get_buffer(proc_private, + d0) + dst_off, + rte_pktmbuf_mtod_offset(mbuf, void *, src_off), + cp_len); + + mq->n_bytes += cp_len; + src_off += cp_len; + dst_off += cp_len; + src_len -= cp_len; + dst_len -= cp_len; + + d0->length = dst_off; + } + + if (--nb_segs > 0) { + mbuf = mbuf->next; + goto next_in_chain2; + } + + n_tx_pkts++; + slot++; + n_free--; + rte_pktmbuf_free(mbuf_head); + } } no_free_slots: -- 2.25.1