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 A1A95A00C5; Thu, 15 Sep 2022 08:58:50 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 3DE94427F7; Thu, 15 Sep 2022 08:58:43 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mails.dpdk.org (Postfix) with ESMTP id F21E14281E for ; Thu, 15 Sep 2022 08:58:41 +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 EC0B31CE0; Wed, 14 Sep 2022 23:58:47 -0700 (PDT) Received: from net-arm-n1sdp-02.shanghai.arm.com (net-arm-n1sdp-02.shanghai.arm.com [10.169.210.140]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 04CB83F73B; Wed, 14 Sep 2022 23:59:07 -0700 (PDT) From: Joyce Kong To: jgrajcia@cisco.com, stephen@networkplumber.org Cc: dev@dpdk.org, nd@arm.com, Joyce Kong Subject: [PATCH v4 2/2] net/memif: add a Tx fast path Date: Thu, 15 Sep 2022 14:58:25 +0800 Message-Id: <20220915065825.26169-3-joyce.kong@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220915065825.26169-1-joyce.kong@arm.com> References: <20220412093243.3670187-1-joyce.kong@arm.com> <20220915065825.26169-1-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 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 | 10.82% | 0.04% | -------------------------------------------- zc gain | 8.86% | 3.18% | -------------------------------------------- Test with 1p1q on Cascade Lake Xeon X86server, -------------------------------------------- buf size | memif >= mbuf | memif < mbuf | -------------------------------------------- non-zc gain | 7.32% | -0.85% | -------------------------------------------- zc gain | 12.75% | -0.16% | -------------------------------------------- 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 762293f636..b5bed955ed 100644 --- a/drivers/net/memif/rte_eth_memif.c +++ b/drivers/net/memif/rte_eth_memif.c @@ -680,62 +680,112 @@ 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: -- 2.17.1