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authorwilly tarreau <w@1wt.eu>2014-01-16 11:20:07 +0400
committerDavid S. Miller <davem@davemloft.net>2014-01-17 03:15:41 +0400
commitdc4277dd41a80fd5f29a90412ea04bc3ba54fbf1 (patch)
tree9b21715c23657d4cd3cc6ae1af4bd827c0625647
parenta81ab36bf52d0ca3a32251a923be1dbced726141 (diff)
downloadlinux-dc4277dd41a80fd5f29a90412ea04bc3ba54fbf1.tar.xz
net: mvneta: increase the 64-bit rx/tx stats out of the hot path
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 <thomas.petazzoni@free-electrons.com> Cc: Gregory CLEMENT <gregory.clement@free-electrons.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Tested-by: Arnaud Ebalard <arno@natisbad.org> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/marvell/mvneta.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index d5f0d72e5e33..baa85af96041 100644
--- 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 *pp, int rx_todo,
{
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 *pp, int rx_todo,
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 *pp, int rx_todo,
}
}
+ 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);