From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by dpdk.org (Postfix) with ESMTP id AC63AD59A for ; Sat, 4 Feb 2017 10:37:31 +0100 (CET) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 76BA5707; Sat, 4 Feb 2017 01:37:28 -0800 (PST) Received: from localhost.localdomain.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id A261A3F477; Sat, 4 Feb 2017 01:37:27 -0800 (PST) From: Jianbo Liu To: dev@dpdk.org, helin.zhang@intel.com, konstantin.ananyev@intel.com, jerin.jacob@caviumnetworks.com Cc: Jianbo Liu Date: Sat, 4 Feb 2017 17:37:03 +0800 Message-Id: <1486201024-32656-1-git-send-email-jianbo.liu@linaro.org> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1482127758-4904-1-git-send-email-jianbo.liu@linaro.org> References: <1482127758-4904-1-git-send-email-jianbo.liu@linaro.org> Subject: [dpdk-dev] [PATCH v2 1/2] net/ixgbe: calculate the correct number of received packets in bulk alloc function X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 04 Feb 2017 09:37:31 -0000 To get better performance, Rx bulk alloc recv function will scan 8 descs in one time, but the statuses are not consistent on ARM platform because the memory allocated for Rx descriptors is cacheable hugepages. This patch is to calculate the number of received packets by scan DD bit sequentially, and stops when meeting the first packet with DD bit unset. Signed-off-by: Jianbo Liu --- drivers/net/ixgbe/ixgbe_rxtx.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c index 36f1c02..613890e 100644 --- a/drivers/net/ixgbe/ixgbe_rxtx.c +++ b/drivers/net/ixgbe/ixgbe_rxtx.c @@ -1460,17 +1460,19 @@ static inline int __attribute__((always_inline)) for (i = 0; i < RTE_PMD_IXGBE_RX_MAX_BURST; i += LOOK_AHEAD, rxdp += LOOK_AHEAD, rxep += LOOK_AHEAD) { /* Read desc statuses backwards to avoid race condition */ - for (j = LOOK_AHEAD-1; j >= 0; --j) + for (j = 0; j < LOOK_AHEAD; j++) s[j] = rte_le_to_cpu_32(rxdp[j].wb.upper.status_error); - for (j = LOOK_AHEAD - 1; j >= 0; --j) - pkt_info[j] = rte_le_to_cpu_32(rxdp[j].wb.lower. - lo_dword.data); + rte_smp_rmb(); /* Compute how many status bits were set */ - nb_dd = 0; - for (j = 0; j < LOOK_AHEAD; ++j) - nb_dd += s[j] & IXGBE_RXDADV_STAT_DD; + for (nb_dd = 0; nb_dd < LOOK_AHEAD && + (s[nb_dd] & IXGBE_RXDADV_STAT_DD); nb_dd++) + ; + + for (j = 0; j < nb_dd; j++) + pkt_info[j] = rte_le_to_cpu_32(rxdp[j].wb.lower. + lo_dword.data); nb_rx += nb_dd; -- 1.8.3.1