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| author | Jesse Brandeburg <jesse.brandeburg@intel.com> | 2006-12-15 10:40:39 +0100 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2006-12-26 15:51:30 -0500 |
| commit | 1f753861d272e648f3234e4f5fdea9434ae7bee4 (patch) | |
| tree | ae34cd182d14e4f736a2acac3079b16f0d47a67b | |
| parent | 018ea44ef1eade417296c4a57afe3cd963268433 (diff) | |
| download | lwn-1f753861d272e648f3234e4f5fdea9434ae7bee4.tar.gz lwn-1f753861d272e648f3234e4f5fdea9434ae7bee4.zip | |
[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>
| -rw-r--r-- | drivers/net/e1000/e1000_main.c | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c index 6c3618d55d15..3f40a902de64 100644 --- a/drivers/net/e1000/e1000_main.c +++ b/drivers/net/e1000/e1000_main.c @@ -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 |