The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1a0f25a52e08b1f67510cabbb44888d2b3c46359 Mon Sep 17 00:00:00 2001
From: Jesse Brandeburg jesse.brandeburg@intel.com Date: Fri, 12 Nov 2021 17:06:02 -0800 Subject: [PATCH] ice: safer stats processing
The driver was zeroing live stats that could be fetched by ndo_get_stats64 at any time. This could result in inconsistent statistics, and the telltale sign was when reading stats frequently from /proc/net/dev, the stats would go backwards.
Fix by collecting stats into a local, and delaying when we write to the structure so it's not incremental.
Fixes: fcea6f3da546 ("ice: Add stats and ethtool support") Signed-off-by: Jesse Brandeburg jesse.brandeburg@intel.com Tested-by: Gurucharan G gurucharanx.g@intel.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c index c6d6ce52e2ca..73c61cdb036f 100644 --- a/drivers/net/ethernet/intel/ice/ice_main.c +++ b/drivers/net/ethernet/intel/ice/ice_main.c @@ -5930,14 +5930,15 @@ ice_fetch_u64_stats_per_ring(struct u64_stats_sync *syncp, struct ice_q_stats st /** * ice_update_vsi_tx_ring_stats - Update VSI Tx ring stats counters * @vsi: the VSI to be updated + * @vsi_stats: the stats struct to be updated * @rings: rings to work on * @count: number of rings */ static void -ice_update_vsi_tx_ring_stats(struct ice_vsi *vsi, struct ice_tx_ring **rings, - u16 count) +ice_update_vsi_tx_ring_stats(struct ice_vsi *vsi, + struct rtnl_link_stats64 *vsi_stats, + struct ice_tx_ring **rings, u16 count) { - struct rtnl_link_stats64 *vsi_stats = &vsi->net_stats; u16 i;
for (i = 0; i < count; i++) { @@ -5961,15 +5962,13 @@ ice_update_vsi_tx_ring_stats(struct ice_vsi *vsi, struct ice_tx_ring **rings, */ static void ice_update_vsi_ring_stats(struct ice_vsi *vsi) { - struct rtnl_link_stats64 *vsi_stats = &vsi->net_stats; + struct rtnl_link_stats64 *vsi_stats; u64 pkts, bytes; int i;
- /* reset netdev stats */ - vsi_stats->tx_packets = 0; - vsi_stats->tx_bytes = 0; - vsi_stats->rx_packets = 0; - vsi_stats->rx_bytes = 0; + vsi_stats = kzalloc(sizeof(*vsi_stats), GFP_ATOMIC); + if (!vsi_stats) + return;
/* reset non-netdev (extended) stats */ vsi->tx_restart = 0; @@ -5981,7 +5980,8 @@ static void ice_update_vsi_ring_stats(struct ice_vsi *vsi) rcu_read_lock();
/* update Tx rings counters */ - ice_update_vsi_tx_ring_stats(vsi, vsi->tx_rings, vsi->num_txq); + ice_update_vsi_tx_ring_stats(vsi, vsi_stats, vsi->tx_rings, + vsi->num_txq);
/* update Rx rings counters */ ice_for_each_rxq(vsi, i) { @@ -5996,10 +5996,17 @@ static void ice_update_vsi_ring_stats(struct ice_vsi *vsi)
/* update XDP Tx rings counters */ if (ice_is_xdp_ena_vsi(vsi)) - ice_update_vsi_tx_ring_stats(vsi, vsi->xdp_rings, + ice_update_vsi_tx_ring_stats(vsi, vsi_stats, vsi->xdp_rings, vsi->num_xdp_txq);
rcu_read_unlock(); + + vsi->net_stats.tx_packets = vsi_stats->tx_packets; + vsi->net_stats.tx_bytes = vsi_stats->tx_bytes; + vsi->net_stats.rx_packets = vsi_stats->rx_packets; + vsi->net_stats.rx_bytes = vsi_stats->rx_bytes; + + kfree(vsi_stats); }
/**