sfc: Implement adaptive IRQ moderation
Calculate a score for each 1000 IRQs:
- TX completions are worth 1 point
- RX completions are worth 4 if merged using LRO or 2 otherwise
Reduce moderation if the score is less than 10000, down to a minimum
of 5 us. Increase moderation if the score is more than 20000, up to
the specified maximum.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sfc/ethtool.c b/drivers/net/sfc/ethtool.c
index 589d132..64309f4 100644
--- a/drivers/net/sfc/ethtool.c
+++ b/drivers/net/sfc/ethtool.c
@@ -604,7 +604,6 @@
{
struct efx_nic *efx = netdev_priv(net_dev);
struct efx_tx_queue *tx_queue;
- struct efx_rx_queue *rx_queue;
struct efx_channel *channel;
memset(coalesce, 0, sizeof(*coalesce));
@@ -622,14 +621,8 @@
}
}
- /* Find lowest IRQ moderation across all used RX queues */
- coalesce->rx_coalesce_usecs_irq = ~((u32) 0);
- efx_for_each_rx_queue(rx_queue, efx) {
- channel = rx_queue->channel;
- if (channel->irq_moderation < coalesce->rx_coalesce_usecs_irq)
- coalesce->rx_coalesce_usecs_irq =
- channel->irq_moderation;
- }
+ coalesce->use_adaptive_rx_coalesce = efx->irq_rx_adaptive;
+ coalesce->rx_coalesce_usecs_irq = efx->irq_rx_moderation;
return 0;
}
@@ -643,10 +636,9 @@
struct efx_nic *efx = netdev_priv(net_dev);
struct efx_channel *channel;
struct efx_tx_queue *tx_queue;
- unsigned tx_usecs, rx_usecs;
+ unsigned tx_usecs, rx_usecs, adaptive;
- if (coalesce->use_adaptive_rx_coalesce ||
- coalesce->use_adaptive_tx_coalesce)
+ if (coalesce->use_adaptive_tx_coalesce)
return -EOPNOTSUPP;
if (coalesce->rx_coalesce_usecs || coalesce->tx_coalesce_usecs) {
@@ -657,6 +649,7 @@
rx_usecs = coalesce->rx_coalesce_usecs_irq;
tx_usecs = coalesce->tx_coalesce_usecs_irq;
+ adaptive = coalesce->use_adaptive_rx_coalesce;
/* If the channel is shared only allow RX parameters to be set */
efx_for_each_tx_queue(tx_queue, efx) {
@@ -668,7 +661,7 @@
}
}
- efx_init_irq_moderation(efx, tx_usecs, rx_usecs);
+ efx_init_irq_moderation(efx, tx_usecs, rx_usecs, adaptive);
/* Reset channel to pick up new moderation value. Note that
* this may change the value of the irq_moderation field