diff options
| author | Tom Herbert <therbert@google.com> | 2010-05-05 14:02:27 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-05-06 04:11:25 (GMT) |
| commit | 9ed318d546a29d7a591dbe648fd1a2efe3be1180 (patch) | |
| tree | adcccd4b9c015d0d81fbce1928c135b269ac1d26 /drivers | |
| parent | 4447957a825031b3faf3b5bc2013afe35eff492b (diff) | |
| download | linux-9ed318d546a29d7a591dbe648fd1a2efe3be1180.tar.xz | |
e1000e: save skb counts in TX to avoid cache misses
In e1000_tx_map, precompute number of segements and bytecounts which
are derived from fields in skb; these are stored in buffer_info. When
cleaning tx in e1000_clean_tx_irq use the values in the associated
buffer_info for statistics counting, this eliminates cache misses
on skb fields.
Signed-off-by: Tom Herbert <therbert@google.com>
Acked-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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/e1000e/e1000.h | 2 | ||||
| -rw-r--r-- | drivers/net/e1000e/netdev.c | 18 |
2 files changed, 11 insertions, 9 deletions
diff --git a/drivers/net/e1000e/e1000.h b/drivers/net/e1000e/e1000.h index 906c4da..c0b3db4 100644 --- a/drivers/net/e1000e/e1000.h +++ b/drivers/net/e1000e/e1000.h @@ -189,6 +189,8 @@ struct e1000_buffer { unsigned long time_stamp; u16 length; u16 next_to_watch; + unsigned int segs; + unsigned int bytecount; u16 mapped_as_page; }; /* Rx */ diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c index d13760d..8de64ed 100644 --- a/drivers/net/e1000e/netdev.c +++ b/drivers/net/e1000e/netdev.c @@ -1001,14 +1001,8 @@ static bool e1000_clean_tx_irq(struct e1000_adapter *adapter) cleaned = (i == eop); if (cleaned) { - struct sk_buff *skb = buffer_info->skb; - unsigned int segs, bytecount; - segs = skb_shinfo(skb)->gso_segs ?: 1; - /* multiply data chunks by size of headers */ - bytecount = ((segs - 1) * skb_headlen(skb)) + - skb->len; - total_tx_packets += segs; - total_tx_bytes += bytecount; + total_tx_packets += buffer_info->segs; + total_tx_bytes += buffer_info->bytecount; } e1000_put_txbuf(adapter, buffer_info); @@ -4261,7 +4255,7 @@ static int e1000_tx_map(struct e1000_adapter *adapter, struct e1000_buffer *buffer_info; unsigned int len = skb_headlen(skb); unsigned int offset = 0, size, count = 0, i; - unsigned int f; + unsigned int f, bytecount, segs; i = tx_ring->next_to_use; @@ -4321,7 +4315,13 @@ static int e1000_tx_map(struct e1000_adapter *adapter, } } + segs = skb_shinfo(skb)->gso_segs ?: 1; + /* multiply data chunks by size of headers */ + bytecount = ((segs - 1) * skb_headlen(skb)) + skb->len; + tx_ring->buffer_info[i].skb = skb; + tx_ring->buffer_info[i].segs = segs; + tx_ring->buffer_info[i].bytecount = bytecount; tx_ring->buffer_info[first].next_to_watch = i; return count; |