igb: fix stats handling
There are currently some problems with igb.
- On 32bit arches, maintaining 64bit counters without proper
synchronization between writers and readers.
- Stats updated every two seconds, as reported by Jesper.
(Jesper provided a patch for this)
- Potential problem between worker thread and ethtool -S
This patch uses u64_stats_sync, and convert everything to be 64bit safe,
SMP safe, even on 32bit arches. It integrates Jesper idea of providing
accurate stats at the time user reads them.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Emil Tantilov <emil.s.tantilov@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/igb/igb_ethtool.c b/drivers/net/igb/igb_ethtool.c
index 26bf6a1..a70e16b 100644
--- a/drivers/net/igb/igb_ethtool.c
+++ b/drivers/net/igb/igb_ethtool.c
@@ -90,8 +90,8 @@
#define IGB_NETDEV_STAT(_net_stat) { \
.stat_string = __stringify(_net_stat), \
- .sizeof_stat = FIELD_SIZEOF(struct net_device_stats, _net_stat), \
- .stat_offset = offsetof(struct net_device_stats, _net_stat) \
+ .sizeof_stat = FIELD_SIZEOF(struct rtnl_link_stats64, _net_stat), \
+ .stat_offset = offsetof(struct rtnl_link_stats64, _net_stat) \
}
static const struct igb_stats igb_gstrings_net_stats[] = {
IGB_NETDEV_STAT(rx_errors),
@@ -111,8 +111,9 @@
(sizeof(igb_gstrings_net_stats) / sizeof(struct igb_stats))
#define IGB_RX_QUEUE_STATS_LEN \
(sizeof(struct igb_rx_queue_stats) / sizeof(u64))
-#define IGB_TX_QUEUE_STATS_LEN \
- (sizeof(struct igb_tx_queue_stats) / sizeof(u64))
+
+#define IGB_TX_QUEUE_STATS_LEN 3 /* packets, bytes, restart_queue */
+
#define IGB_QUEUE_STATS_LEN \
((((struct igb_adapter *)netdev_priv(netdev))->num_rx_queues * \
IGB_RX_QUEUE_STATS_LEN) + \
@@ -2070,12 +2071,14 @@
struct ethtool_stats *stats, u64 *data)
{
struct igb_adapter *adapter = netdev_priv(netdev);
- struct net_device_stats *net_stats = &netdev->stats;
- u64 *queue_stat;
- int i, j, k;
+ struct rtnl_link_stats64 *net_stats = &adapter->stats64;
+ unsigned int start;
+ struct igb_ring *ring;
+ int i, j;
char *p;
- igb_update_stats(adapter);
+ spin_lock(&adapter->stats64_lock);
+ igb_update_stats(adapter, net_stats);
for (i = 0; i < IGB_GLOBAL_STATS_LEN; i++) {
p = (char *)adapter + igb_gstrings_stats[i].stat_offset;
@@ -2088,15 +2091,36 @@
sizeof(u64)) ? *(u64 *)p : *(u32 *)p;
}
for (j = 0; j < adapter->num_tx_queues; j++) {
- queue_stat = (u64 *)&adapter->tx_ring[j]->tx_stats;
- for (k = 0; k < IGB_TX_QUEUE_STATS_LEN; k++, i++)
- data[i] = queue_stat[k];
+ u64 restart2;
+
+ ring = adapter->tx_ring[j];
+ do {
+ start = u64_stats_fetch_begin_bh(&ring->tx_syncp);
+ data[i] = ring->tx_stats.packets;
+ data[i+1] = ring->tx_stats.bytes;
+ data[i+2] = ring->tx_stats.restart_queue;
+ } while (u64_stats_fetch_retry_bh(&ring->tx_syncp, start));
+ do {
+ start = u64_stats_fetch_begin_bh(&ring->tx_syncp2);
+ restart2 = ring->tx_stats.restart_queue2;
+ } while (u64_stats_fetch_retry_bh(&ring->tx_syncp2, start));
+ data[i+2] += restart2;
+
+ i += IGB_TX_QUEUE_STATS_LEN;
}
for (j = 0; j < adapter->num_rx_queues; j++) {
- queue_stat = (u64 *)&adapter->rx_ring[j]->rx_stats;
- for (k = 0; k < IGB_RX_QUEUE_STATS_LEN; k++, i++)
- data[i] = queue_stat[k];
+ ring = adapter->rx_ring[j];
+ do {
+ start = u64_stats_fetch_begin_bh(&ring->rx_syncp);
+ data[i] = ring->rx_stats.packets;
+ data[i+1] = ring->rx_stats.bytes;
+ data[i+2] = ring->rx_stats.drops;
+ data[i+3] = ring->rx_stats.csum_err;
+ data[i+4] = ring->rx_stats.alloc_failed;
+ } while (u64_stats_fetch_retry_bh(&ring->rx_syncp, start));
+ i += IGB_RX_QUEUE_STATS_LEN;
}
+ spin_unlock(&adapter->stats64_lock);
}
static void igb_get_strings(struct net_device *netdev, u32 stringset, u8 *data)