sfc: use tx_queue->old_read_count in EF100 TX path (5374d602) · Commits · 戴 / test

drivers/net/ethernet/sfc/ef100_tx.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -360,15 +360,19 @@ int ef100_enqueue_skb(struct efx_tx_queue tx_queue, struct sk_buff skb)
		goto err;
		ef100_tx_make_descriptors(tx_queue, skb, segments);

		fill_level = efx_channel_tx_fill_level(tx_queue->channel);
		fill_level = efx_channel_tx_old_fill_level(tx_queue->channel);
		if (fill_level > efx->txq_stop_thresh) {
		struct efx_tx_queue *txq2;

		netif_tx_stop_queue(tx_queue->core_txq);
		/* Re-read after a memory barrier in case we've raced with
		* the completion path. Otherwise there's a danger we'll never
		* restart the queue if all completions have just happened.
		*/
		smp_mb();
		fill_level = efx_channel_tx_fill_level(tx_queue->channel);
		efx_for_each_channel_tx_queue(txq2, tx_queue->channel)
		txq2->old_read_count = READ_ONCE(txq2->read_count);
		fill_level = efx_channel_tx_old_fill_level(tx_queue->channel);
		if (fill_level < efx->txq_stop_thresh)
		netif_tx_start_queue(tx_queue->core_txq);
		}

+14 −0

Original line number	Diff line number	Diff line
		@@ -1692,6 +1692,20 @@ efx_channel_tx_fill_level(struct efx_channel *channel)
		return fill_level;
		}

		/* Conservative approximation of efx_channel_tx_fill_level using cached value */
		static inline unsigned int
		efx_channel_tx_old_fill_level(struct efx_channel *channel)
		{
		struct efx_tx_queue *tx_queue;
		unsigned int fill_level = 0;

		efx_for_each_channel_tx_queue(tx_queue, channel)
		fill_level = max(fill_level,
		tx_queue->insert_count - tx_queue->old_read_count);

		return fill_level;
		}

		/* Get all supported features.
		* If a feature is not fixed, it is present in hw_features.
		* If a feature is fixed, it does not present in hw_features, but