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[PATCH] e1000: Make the copybreak value a module parameter 

Allow the user to vary the size that copybreak works. Currently cb is enabled
for packets < 256 bytes, but various tests indicate that this should be
configurable for specific use cases. In addition, this parameter allows us
to force never/always during testing to get full and predictable coverage of
both code paths.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Jesse Brandeburg 2006-12-15 10:40:39 +01:00 committed by Jeff Garzik
parent 018ea44ef1
commit 1f753861d2
1 changed files with 15 additions and 4 deletions
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19
drivers/net/e1000/e1000_main.c
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@ -213,6 +213,12 @@ static void e1000_netpoll (struct net_device *netdev);
extern void e1000_check_options(struct e1000_adapter *adapter);
#define COPYBREAK_DEFAULT 256
static unsigned int copybreak __read_mostly = COPYBREAK_DEFAULT;
module_param(copybreak, uint, 0644);
MODULE_PARM_DESC(copybreak,
"Maximum size of packet that is copied to a new buffer on receive");
static pci_ers_result_t e1000_io_error_detected(struct pci_dev *pdev,
pci_channel_state_t state);
static pci_ers_result_t e1000_io_slot_reset(struct pci_dev *pdev);
@ -264,7 +270,13 @@ e1000_init_module(void)
printk(KERN_INFO "%s\n", e1000_copyright);
ret = pci_register_driver(&e1000_driver);
if (copybreak != COPYBREAK_DEFAULT) {
if (copybreak == 0)
printk(KERN_INFO "e1000: copybreak disabled\n");
else
printk(KERN_INFO "e1000: copybreak enabled for "
"packets <= %u bytes\n", copybreak);
}
return ret;
}
@ -4235,8 +4247,7 @@ e1000_clean_rx_irq(struct e1000_adapter *adapter,
/* code added for copybreak, this should improve
* performance for small packets with large amounts
* of reassembly being done in the stack */
#define E1000_CB_LENGTH 256
if (length < E1000_CB_LENGTH) {
if (length < copybreak) {
struct sk_buff *new_skb =
netdev_alloc_skb(netdev, length + NET_IP_ALIGN);
if (new_skb) {
@ -4394,7 +4405,7 @@ e1000_clean_rx_irq_ps(struct e1000_adapter *adapter,
/* page alloc/put takes too long and effects small packet
* throughput, so unsplit small packets and save the alloc/put*/
if (l1 && ((length + l1) <= adapter->rx_ps_bsize0)) {
if (l1 && (l1 <= copybreak) && ((length + l1) <= adapter->rx_ps_bsize0)) {
u8 *vaddr;
/* there is no documentation about how to call
* kmap_atomic, so we can't hold the mapping