[net 07/15] net/mlx5e: Replace synchronize_rcu with synchronize_net
From: Saeed Mahameed <saeed@kernel.org>
Date: 2021-02-12 02:59:05
Subsystem:
mellanox ethernet driver (mlx5e), mellanox ethernet innova drivers, mellanox mlx5 core vpi driver, networking drivers, the rest, xdp (express data path) · Maintainers:
Saeed Mahameed, Tariq Toukan, Mark Bloch, Leon Romanovsky, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Alexei Starovoitov, Daniel Borkmann, Jesper Dangaard Brouer, John Fastabend
From: Maxim Mikityanskiy <redacted>
The commit cited below switched from using napi_synchronize to
synchronize_rcu to have a guarantee that it will finish in finite time.
However, on average, synchronize_rcu takes more time than
napi_synchronize. Given that it's called multiple times per channel on
deactivation, it accumulates to a significant amount, which causes
timeouts in some applications (for example, when using bonding with
NetworkManager).
This commit replaces synchronize_rcu with synchronize_net, which is
faster when called under rtnl_lock, allowing to speed up the described
flow.
Fixes: 9c25a22dfb00 ("net/mlx5e: Use synchronize_rcu to sync with NAPI")
Signed-off-by: Maxim Mikityanskiy <redacted>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
---
drivers/net/ethernet/mellanox/mlx5/core/en/xdp.h | 2 +-
drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c | 2 +-
.../net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c | 2 +-
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 8 ++++----
4 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.h b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.h
index d487e5e37162..8d991c3b7a50 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.h@@ -83,7 +83,7 @@ static inline void mlx5e_xdp_tx_disable(struct mlx5e_priv *priv) clear_bit(MLX5E_STATE_XDP_TX_ENABLED, &priv->state); /* Let other device's napi(s) and XSK wakeups see our new state. */ - synchronize_rcu(); + synchronize_net(); } static inline bool mlx5e_xdp_tx_is_enabled(struct mlx5e_priv *priv)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c
index d87c345878d3..f4bce1365639 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c@@ -111,7 +111,7 @@ int mlx5e_open_xsk(struct mlx5e_priv *priv, struct mlx5e_params *params, void mlx5e_close_xsk(struct mlx5e_channel *c) { clear_bit(MLX5E_CHANNEL_STATE_XSK, c->state); - synchronize_rcu(); /* Sync with the XSK wakeup and with NAPI. */ + synchronize_net(); /* Sync with the XSK wakeup and with NAPI. */ mlx5e_close_rq(&c->xskrq); mlx5e_close_cq(&c->xskrq.cq);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c
index 6a1d82503ef8..0f13b661f7f9 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c@@ -663,7 +663,7 @@ void mlx5e_ktls_del_rx(struct net_device *netdev, struct tls_context *tls_ctx) priv_rx = mlx5e_get_ktls_rx_priv_ctx(tls_ctx); set_bit(MLX5E_PRIV_RX_FLAG_DELETING, priv_rx->flags); mlx5e_set_ktls_rx_priv_ctx(tls_ctx, NULL); - synchronize_rcu(); /* Sync with NAPI */ + synchronize_net(); /* Sync with NAPI */ if (!cancel_work_sync(&priv_rx->rule.work)) /* completion is needed, as the priv_rx in the add flow * is maintained on the wqe info (wi), not on the socket.
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 5052820f7a51..3edc826cc6bb 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c@@ -915,7 +915,7 @@ void mlx5e_activate_rq(struct mlx5e_rq *rq) void mlx5e_deactivate_rq(struct mlx5e_rq *rq) { clear_bit(MLX5E_RQ_STATE_ENABLED, &rq->state); - synchronize_rcu(); /* Sync with NAPI to prevent mlx5e_post_rx_wqes. */ + synchronize_net(); /* Sync with NAPI to prevent mlx5e_post_rx_wqes. */ } void mlx5e_close_rq(struct mlx5e_rq *rq)
@@ -1349,7 +1349,7 @@ void mlx5e_deactivate_txqsq(struct mlx5e_txqsq *sq) struct mlx5_wq_cyc *wq = &sq->wq; clear_bit(MLX5E_SQ_STATE_ENABLED, &sq->state); - synchronize_rcu(); /* Sync with NAPI to prevent netif_tx_wake_queue. */ + synchronize_net(); /* Sync with NAPI to prevent netif_tx_wake_queue. */ mlx5e_tx_disable_queue(sq->txq);
@@ -1424,7 +1424,7 @@ void mlx5e_activate_icosq(struct mlx5e_icosq *icosq) void mlx5e_deactivate_icosq(struct mlx5e_icosq *icosq) { clear_bit(MLX5E_SQ_STATE_ENABLED, &icosq->state); - synchronize_rcu(); /* Sync with NAPI. */ + synchronize_net(); /* Sync with NAPI. */ } void mlx5e_close_icosq(struct mlx5e_icosq *sq)
@@ -1503,7 +1503,7 @@ void mlx5e_close_xdpsq(struct mlx5e_xdpsq *sq) struct mlx5e_channel *c = sq->channel; clear_bit(MLX5E_SQ_STATE_ENABLED, &sq->state); - synchronize_rcu(); /* Sync with NAPI. */ + synchronize_net(); /* Sync with NAPI. */ mlx5e_destroy_sq(c->mdev, sq->sqn); mlx5e_free_xdpsq_descs(sq);
--
2.29.2