This fix attempts to solve a customer (IBM) reported issue with NAPI enabled e1000 having bad performance when transmitting simultaneously on four ports. The issue comes down to an interaction between NAPI, hardware interrupt balancing, and the driver rescheduling poll on the same processor. Try to fix by allowing the driver to re-enable interrupts sooner instead of polling one more time, when there was recently all the work completed in cleanup.
Signed-off-by: Jesse Brandeburg <[EMAIL PROTECTED]> Signed-off-by: Auke Kok <[EMAIL PROTECTED]> --- drivers/net/e1000/e1000_main.c | 13 ++++++++----- 1 files changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c index d408949..ab1b40f 100644 --- a/drivers/net/e1000/e1000_main.c +++ b/drivers/net/e1000/e1000_main.c @@ -3814,7 +3814,7 @@ e1000_intr_msi(int irq, void *data) for (i = 0; i < E1000_MAX_INTR; i++) if (unlikely(!adapter->clean_rx(adapter, adapter->rx_ring) & - !e1000_clean_tx_irq(adapter, adapter->tx_ring))) + e1000_clean_tx_irq(adapter, adapter->tx_ring))) break; if (likely(adapter->itr_setting & 3)) @@ -3917,7 +3917,7 @@ e1000_intr(int irq, void *data) for (i = 0; i < E1000_MAX_INTR; i++) if (unlikely(!adapter->clean_rx(adapter, adapter->rx_ring) & - !e1000_clean_tx_irq(adapter, adapter->tx_ring))) + e1000_clean_tx_irq(adapter, adapter->tx_ring))) break; if (likely(adapter->itr_setting & 3)) @@ -3967,7 +3967,7 @@ e1000_clean(struct net_device *poll_dev, int *budget) poll_dev->quota -= work_done; /* If no Tx and not enough Rx work done, exit the polling mode */ - if ((!tx_cleaned && (work_done == 0)) || + if ((tx_cleaned && (work_done < work_to_do)) || !netif_running(poll_dev)) { quit_polling: if (likely(adapter->itr_setting & 3)) @@ -3997,7 +3997,7 @@ e1000_clean_tx_irq(struct e1000_adapter *adapter, #ifdef CONFIG_E1000_NAPI unsigned int count = 0; #endif - boolean_t cleaned = FALSE; + boolean_t cleaned = TRUE; unsigned int total_tx_bytes=0, total_tx_packets=0; i = tx_ring->next_to_clean; @@ -4028,7 +4028,10 @@ e1000_clean_tx_irq(struct e1000_adapter *adapter, #ifdef CONFIG_E1000_NAPI #define E1000_TX_WEIGHT 64 /* weight of a sort for tx, to avoid endless transmit cleanup */ - if (count++ == E1000_TX_WEIGHT) break; + if (count++ == E1000_TX_WEIGHT) { + cleaned = FALSE; + break; + } #endif } --- Auke Kok <[EMAIL PROTECTED]> - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html