diff options
| author | Íñigo Huguet <ihuguet@redhat.com> | 2021-09-09 11:28:46 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-09-09 11:17:37 +0100 |
| commit | 6215b608a8c4d4a478721e14a6faa0dc56e4a693 (patch) | |
| tree | 431f8e5d54c7145882a05f1819e238209088a79b /drivers/net/ethernet/sfc/tx.c | |
| parent | 415446185b939dcdcd6a483e705c805ab961e54c (diff) | |
sfc: last resort fallback for lack of xdp tx queues
Previous patch addressed the situation of having some free resources for
xdp tx but not enough for one tx queue per CPU. This patch address the
worst case of not having resources at all for xdp tx.
Instead of using queues dedicated to xdp, normal queues used by network
stack are shared for both cases, using __netif_tx_lock for
synchronization. Also queue stop/restart must be considered in the xdp
path to avoid freezing the queue.
This is not the ideal situation we might want to be, and a performance
penalty is expected both for normal and xdp traffic, but at least XDP
will work in all possible situations (with a warning in the logs),
improving a bit the pain of not knowing in what situations we can use it
and in what situations we cannot.
Signed-off-by: Íñigo Huguet <ihuguet@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/sfc/tx.c')
| -rw-r--r-- | drivers/net/ethernet/sfc/tx.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c index c7afd6cda902..d16e031e95f4 100644 --- a/drivers/net/ethernet/sfc/tx.c +++ b/drivers/net/ethernet/sfc/tx.c @@ -428,10 +428,8 @@ int efx_xdp_tx_buffers(struct efx_nic *efx, int n, struct xdp_frame **xdpfs, unsigned int len; int space; int cpu; - int i; + int i = 0; - if (unlikely(efx->xdp_txq_queues_mode == EFX_XDP_TX_QUEUES_DISABLED)) - return -EINVAL; if (unlikely(n && !xdpfs)) return -EINVAL; if (unlikely(!n)) @@ -448,6 +446,15 @@ int efx_xdp_tx_buffers(struct efx_nic *efx, int n, struct xdp_frame **xdpfs, if (efx->xdp_txq_queues_mode != EFX_XDP_TX_QUEUES_DEDICATED) HARD_TX_LOCK(efx->net_dev, tx_queue->core_txq, cpu); + /* If we're borrowing net stack queues we have to handle stop-restart + * or we might block the queue and it will be considered as frozen + */ + if (efx->xdp_txq_queues_mode == EFX_XDP_TX_QUEUES_BORROWED) { + if (netif_tx_queue_stopped(tx_queue->core_txq)) + goto unlock; + efx_tx_maybe_stop_queue(tx_queue); + } + /* Check for available space. We should never need multiple * descriptors per frame. */ @@ -486,6 +493,7 @@ int efx_xdp_tx_buffers(struct efx_nic *efx, int n, struct xdp_frame **xdpfs, if (flush && i > 0) efx_nic_push_buffers(tx_queue); +unlock: if (efx->xdp_txq_queues_mode != EFX_XDP_TX_QUEUES_DEDICATED) HARD_TX_UNLOCK(efx->net_dev, tx_queue->core_txq); |