Commit 4d6e6b0c authored by Maxim Mikityanskiy's avatar Maxim Mikityanskiy Committed by Saeed Mahameed
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net/mlx5e: Replace synchronize_rcu with synchronize_net 



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: 9c25a22d ("net/mlx5e: Use synchronize_rcu to sync with NAPI")
Signed-off-by: default avatarMaxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: default avatarTariq Toukan <tariqt@nvidia.com>
Signed-off-by: default avatarSaeed Mahameed <saeedm@nvidia.com>
parent 51d138c2

drivers/net/ethernet/mellanox/mlx5/core/en/xdp.h

+1 −1
Original line number Diff line number Diff line
@@ -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)

drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c

+1 −1
Original line number Diff line number Diff line
@@ -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.

drivers/net/ethernet/mellanox/mlx5/core/en_main.c

+4 −4
Original line number Diff line number Diff line
@@ -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);