diff options
| author | Maxim Mikityanskiy <maximmi@mellanox.com> | 2020-06-11 14:25:19 +0300 |
|---|---|---|
| committer | Saeed Mahameed <saeedm@nvidia.com> | 2020-09-21 17:22:21 -0700 |
| commit | 9c25a22dfb00270372224721fed646965420323a (patch) | |
| tree | 7aa5cd4729b74d75ce128a227504ddffbbd7752e /drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c | |
| parent | fe45386a208277cae4648106133c08246eecd012 (diff) | |
net/mlx5e: Use synchronize_rcu to sync with NAPI
As described in the previous commit, napi_synchronize doesn't quite fit
the purpose when we just need to wait until the currently running NAPI
quits. Its implementation waits until NAPI is not running by polling and
waiting for 1ms in between. In cases where we need to deactivate one
queue (e.g., recovery flows) or where we deactivate them one-by-one
(deactivate channel flow), we may get stuck in napi_synchronize forever
if other queues keep NAPI active, causing a soft lockup. Depending on
kernel configuration (CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC), it may result
in a kernel panic.
To fix the issue, use synchronize_rcu to wait for NAPI to quit, and wrap
the whole NAPI in rcu_read_lock.
Fixes: acc6c5953af1 ("net/mlx5e: Split open/close channels to stages")
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Diffstat (limited to 'drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c | 3 |
1 files changed, 1 insertions, 2 deletions
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 dd9df519d383..55e65a438de7 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c @@ -106,8 +106,7 @@ err_free_cparam: void mlx5e_close_xsk(struct mlx5e_channel *c) { clear_bit(MLX5E_CHANNEL_STATE_XSK, c->state); - napi_synchronize(&c->napi); - synchronize_rcu(); /* Sync with the XSK wakeup. */ + synchronize_rcu(); /* Sync with the XSK wakeup and with NAPI. */ mlx5e_close_rq(&c->xskrq); mlx5e_close_cq(&c->xskrq.cq); |