leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

e1000: fix NAPI performance on 4-port adapters

Browse Source 
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 <jesse.brandeburg@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
This commit is contained in:
Jesse Brandeburg 2007-01-18 09:25:23 -08:00 committed by Jeff Garzik
parent b5fc8f0c43
commit 60cba200f1
1 changed files with 8 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
drivers/net/e1000/e1000_main.c
View File

@ -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
}