Using volatile for statistics generates expensive atomic rmw operations when not necessary.
Signed-off-by: Stephen Hemminger <[email protected]> --- drivers/net/pcap/pcap_ethdev.c | 38 ++++++++++++++++++++++++++-------- 1 file changed, 29 insertions(+), 9 deletions(-) diff --git a/drivers/net/pcap/pcap_ethdev.c b/drivers/net/pcap/pcap_ethdev.c index 1658685a28..175d6998f9 100644 --- a/drivers/net/pcap/pcap_ethdev.c +++ b/drivers/net/pcap/pcap_ethdev.c @@ -47,10 +47,10 @@ static uint64_t timestamp_rx_dynflag; static int timestamp_dynfield_offset = -1; struct queue_stat { - volatile unsigned long pkts; - volatile unsigned long bytes; - volatile unsigned long err_pkts; - volatile unsigned long rx_nombuf; + uint64_t pkts; + uint64_t bytes; + uint64_t err_pkts; + uint64_t rx_nombuf; }; struct queue_missed_stat { @@ -267,6 +267,9 @@ eth_pcap_rx_infinite(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts) pcap_q->rx_stat.pkts += i; pcap_q->rx_stat.bytes += rx_bytes; + /* ensure store operations of statistics are visible */ + rte_atomic_thread_fence(rte_memory_order_release); + return i; } @@ -345,6 +348,9 @@ eth_pcap_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts) pcap_q->rx_stat.pkts += num_rx; pcap_q->rx_stat.bytes += rx_bytes; + /* ensure store operations of statistics are visible */ + rte_atomic_thread_fence(rte_memory_order_release); + return num_rx; } @@ -440,6 +446,9 @@ eth_pcap_tx_dumper(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts) dumper_q->tx_stat.bytes += tx_bytes; dumper_q->tx_stat.err_pkts += nb_pkts - num_tx; + /* ensure store operations of statistics are visible */ + rte_atomic_thread_fence(rte_memory_order_release); + return nb_pkts; } @@ -464,6 +473,9 @@ eth_tx_drop(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts) tx_queue->tx_stat.pkts += nb_pkts; tx_queue->tx_stat.bytes += tx_bytes; + /* ensure store operations of statistics are visible */ + rte_atomic_thread_fence(rte_memory_order_release); + return nb_pkts; } @@ -515,6 +527,9 @@ eth_pcap_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts) tx_queue->tx_stat.bytes += tx_bytes; tx_queue->tx_stat.err_pkts += nb_pkts - num_tx; + /* ensure store operations of statistics are visible */ + rte_atomic_thread_fence(rte_memory_order_release); + return nb_pkts; } @@ -821,13 +836,16 @@ eth_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats, struct eth_queue_stats *qstats) { unsigned int i; - unsigned long rx_packets_total = 0, rx_bytes_total = 0; - unsigned long rx_missed_total = 0; - unsigned long rx_nombuf_total = 0, rx_err_total = 0; - unsigned long tx_packets_total = 0, tx_bytes_total = 0; - unsigned long tx_packets_err_total = 0; + uint64_t rx_packets_total = 0, rx_bytes_total = 0; + uint64_t rx_missed_total = 0; + uint64_t rx_nombuf_total = 0, rx_err_total = 0; + uint64_t tx_packets_total = 0, tx_bytes_total = 0; + uint64_t tx_packets_err_total = 0; const struct pmd_internals *internal = dev->data->dev_private; + /* ensure that current statistics are visible */ + rte_atomic_thread_fence(rte_memory_order_acquire); + for (i = 0; i < RTE_ETHDEV_QUEUE_STAT_CNTRS && i < dev->data->nb_rx_queues; i++) { if (qstats != NULL) { @@ -884,6 +902,8 @@ eth_stats_reset(struct rte_eth_dev *dev) internal->tx_queue[i].tx_stat.err_pkts = 0; } + /* ensure store operations of statistics are visible */ + rte_atomic_thread_fence(rte_memory_order_release); return 0; } -- 2.51.0
