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authorPetr Machata <petrm@mellanox.com>2020-01-15 12:53:48 +0100
committerDavid S. Miller <davem@davemloft.net>2020-01-15 13:16:30 +0100
commitca7609ff3680c51d6c29897f3117aa2ad904f92a (patch)
tree00729c263f1d1271ad8cc8de5085efebcad775f2
parentselftests: mlxsw: qos_mc_aware: Fix mausezahn invocation (diff)
downloadlinux-ca7609ff3680c51d6c29897f3117aa2ad904f92a.tar.xz
linux-ca7609ff3680c51d6c29897f3117aa2ad904f92a.zip
mlxsw: spectrum: Wipe xstats.backlog of down ports
Per-port counter cache used by Qdiscs is updated periodically, unless the port is down. The fact that the cache is not updated for down ports is no problem for most counters, which are relative in nature. However, backlog is absolute in nature, and if there is a non-zero value in the cache around the time that the port goes down, that value just stays there. This value then leaks to offloaded Qdiscs that report non-zero backlog even if there (obviously) is no traffic. The HW does not keep backlog of a downed port, so do likewise: as the port goes down, wipe the backlog value from xstats. Fixes: 075ab8adaf4e ("mlxsw: spectrum: Collect tclass related stats periodically") Signed-off-by: Petr Machata <petrm@mellanox.com> Acked-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/mellanox/mlxsw/spectrum.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
index 2394c425b47d..8ed15199eb4f 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c
@@ -1209,6 +1209,9 @@ static void update_stats_cache(struct work_struct *work)
periodic_hw_stats.update_dw.work);
if (!netif_carrier_ok(mlxsw_sp_port->dev))
+ /* Note: mlxsw_sp_port_down_wipe_counters() clears the cache as
+ * necessary when port goes down.
+ */
goto out;
mlxsw_sp_port_get_hw_stats(mlxsw_sp_port->dev,
@@ -4318,6 +4321,15 @@ static int mlxsw_sp_port_unsplit(struct mlxsw_core *mlxsw_core, u8 local_port,
return 0;
}
+static void
+mlxsw_sp_port_down_wipe_counters(struct mlxsw_sp_port *mlxsw_sp_port)
+{
+ int i;
+
+ for (i = 0; i < TC_MAX_QUEUE; i++)
+ mlxsw_sp_port->periodic_hw_stats.xstats.backlog[i] = 0;
+}
+
static void mlxsw_sp_pude_event_func(const struct mlxsw_reg_info *reg,
char *pude_pl, void *priv)
{
@@ -4339,6 +4351,7 @@ static void mlxsw_sp_pude_event_func(const struct mlxsw_reg_info *reg,
} else {
netdev_info(mlxsw_sp_port->dev, "link down\n");
netif_carrier_off(mlxsw_sp_port->dev);
+ mlxsw_sp_port_down_wipe_counters(mlxsw_sp_port);
}
}