e1000e: drop lltx, remove unnecessary lock

LLTX is deprecated and complicated, don't use it.  It was observed by Don Ash
<donash4@gmail.com> that e1000e was acquiring this lock in the NAPI cleanup
path.  This is obviously a bug, as this is a leftover from when e1000
supported multiple tx queues and fake netdevs.

another user reported this to us and tested routing with the 2.6.27 kernel and
this patch and reported a 3.5 % improvement in packets forwarded in a
multi-port test on 82571 parts.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jesse Brandeburg 2009-01-19 14:17:08 +00:00 committed by David S. Miller
parent 5ef3041e4a
commit 92af3e95e4
2 changed files with 3 additions and 33 deletions

View File

@ -195,8 +195,6 @@ struct e1000_adapter {
u16 link_duplex;
u16 eeprom_vers;
spinlock_t tx_queue_lock; /* prevent concurrent tail updates */
/* track device up/down/testing state */
unsigned long state;

View File

@ -47,7 +47,7 @@
#include "e1000.h"
#define DRV_VERSION "0.3.3.3-k6"
#define DRV_VERSION "0.3.3.4-k2"
char e1000e_driver_name[] = "e1000e";
const char e1000e_driver_version[] = DRV_VERSION;
@ -1698,7 +1698,6 @@ int e1000e_setup_tx_resources(struct e1000_adapter *adapter)
tx_ring->next_to_use = 0;
tx_ring->next_to_clean = 0;
spin_lock_init(&adapter->tx_queue_lock);
return 0;
err:
@ -2007,16 +2006,7 @@ static int e1000_clean(struct napi_struct *napi, int budget)
!(adapter->rx_ring->ims_val & adapter->tx_ring->ims_val))
goto clean_rx;
/*
* e1000_clean is called per-cpu. This lock protects
* tx_ring from being cleaned by multiple cpus
* simultaneously. A failure obtaining the lock means
* tx_ring is currently being cleaned anyway.
*/
if (spin_trylock(&adapter->tx_queue_lock)) {
tx_cleaned = e1000_clean_tx_irq(adapter);
spin_unlock(&adapter->tx_queue_lock);
}
tx_cleaned = e1000_clean_tx_irq(adapter);
clean_rx:
adapter->clean_rx(adapter, &work_done, budget);
@ -2922,8 +2912,6 @@ static int __devinit e1000_sw_init(struct e1000_adapter *adapter)
if (e1000_alloc_queues(adapter))
return -ENOMEM;
spin_lock_init(&adapter->tx_queue_lock);
/* Explicitly disable IRQ since the NIC can be in any state. */
e1000_irq_disable(adapter);
@ -4069,7 +4057,6 @@ static int e1000_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
unsigned int max_txd_pwr = E1000_MAX_TXD_PWR;
unsigned int tx_flags = 0;
unsigned int len = skb->len - skb->data_len;
unsigned long irq_flags;
unsigned int nr_frags;
unsigned int mss;
int count = 0;
@ -4138,18 +4125,12 @@ static int e1000_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
if (adapter->hw.mac.tx_pkt_filtering)
e1000_transfer_dhcp_info(adapter, skb);
if (!spin_trylock_irqsave(&adapter->tx_queue_lock, irq_flags))
/* Collision - tell upper layer to requeue */
return NETDEV_TX_LOCKED;
/*
* need: count + 2 desc gap to keep tail from touching
* head, otherwise try next time
*/
if (e1000_maybe_stop_tx(netdev, count + 2)) {
spin_unlock_irqrestore(&adapter->tx_queue_lock, irq_flags);
if (e1000_maybe_stop_tx(netdev, count + 2))
return NETDEV_TX_BUSY;
}
if (adapter->vlgrp && vlan_tx_tag_present(skb)) {
tx_flags |= E1000_TX_FLAGS_VLAN;
@ -4161,7 +4142,6 @@ static int e1000_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
tso = e1000_tso(adapter, skb);
if (tso < 0) {
dev_kfree_skb_any(skb);
spin_unlock_irqrestore(&adapter->tx_queue_lock, irq_flags);
return NETDEV_TX_OK;
}
@ -4182,7 +4162,6 @@ static int e1000_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
if (count < 0) {
/* handle pci_map_single() error in e1000_tx_map */
dev_kfree_skb_any(skb);
spin_unlock_irqrestore(&adapter->tx_queue_lock, irq_flags);
return NETDEV_TX_OK;
}
@ -4193,7 +4172,6 @@ static int e1000_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
/* Make sure there is space in the ring for the next send. */
e1000_maybe_stop_tx(netdev, MAX_SKB_FRAGS + 2);
spin_unlock_irqrestore(&adapter->tx_queue_lock, irq_flags);
return NETDEV_TX_OK;
}
@ -4922,12 +4900,6 @@ static int __devinit e1000_probe(struct pci_dev *pdev,
if (pci_using_dac)
netdev->features |= NETIF_F_HIGHDMA;
/*
* We should not be using LLTX anymore, but we are still Tx faster with
* it.
*/
netdev->features |= NETIF_F_LLTX;
if (e1000e_enable_mng_pass_thru(&adapter->hw))
adapter->flags |= FLAG_MNG_PT_ENABLED;