From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756828AbaCDVXG (ORCPT ); Tue, 4 Mar 2014 16:23:06 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:40958 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756109AbaCDUDU (ORCPT ); Tue, 4 Mar 2014 15:03:20 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Petazzoni , Gregory CLEMENT , Eric Dumazet , Arnaud Ebalard , Willy Tarreau , "David S. Miller" Subject: [PATCH 3.13 057/172] net: mvneta: increase the 64-bit rx/tx stats out of the hot path Date: Tue, 4 Mar 2014 12:02:21 -0800 Message-Id: <20140304200301.553810257@linuxfoundation.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <20140304200259.626667112@linuxfoundation.org> References: <20140304200259.626667112@linuxfoundation.org> User-Agent: quilt/0.61-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: willy tarreau [ Upstream commit dc4277dd41a80fd5f29a90412ea04bc3ba54fbf1 ] Better count packets and bytes in the stack and on 32 bit then accumulate them at the end for once. This saves two memory writes and two memory barriers per packet. The incoming packet rate was increased by 4.7% on the Openblocks AX3 thanks to this. Cc: Thomas Petazzoni Cc: Gregory CLEMENT Reviewed-by: Eric Dumazet Tested-by: Arnaud Ebalard Signed-off-by: Willy Tarreau Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/marvell/mvneta.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -1391,6 +1391,8 @@ static int mvneta_rx(struct mvneta_port { struct net_device *dev = pp->dev; int rx_done, rx_filled; + u32 rcvd_pkts = 0; + u32 rcvd_bytes = 0; /* Get number of received packets */ rx_done = mvneta_rxq_busy_desc_num_get(pp, rxq); @@ -1428,10 +1430,8 @@ static int mvneta_rx(struct mvneta_port rx_bytes = rx_desc->data_size - (ETH_FCS_LEN + MVNETA_MH_SIZE); - u64_stats_update_begin(&pp->rx_stats.syncp); - pp->rx_stats.packets++; - pp->rx_stats.bytes += rx_bytes; - u64_stats_update_end(&pp->rx_stats.syncp); + rcvd_pkts++; + rcvd_bytes += rx_bytes; /* Linux processing */ skb_reserve(skb, MVNETA_MH_SIZE); @@ -1452,6 +1452,13 @@ static int mvneta_rx(struct mvneta_port } } + if (rcvd_pkts) { + u64_stats_update_begin(&pp->rx_stats.syncp); + pp->rx_stats.packets += rcvd_pkts; + pp->rx_stats.bytes += rcvd_bytes; + u64_stats_update_end(&pp->rx_stats.syncp); + } + /* Update rxq management counters */ mvneta_rxq_desc_num_update(pp, rxq, rx_done, rx_filled);