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authorTom Herbert <therbert@google.com>2010-05-05 14:02:27 +0000
committerDavid S. Miller <davem@davemloft.net>2010-05-05 21:11:25 -0700
commit9ed318d546a29d7a591dbe648fd1a2efe3be1180 (patch)
treeadcccd4b9c015d0d81fbce1928c135b269ac1d26 /drivers/net/e1000e
parent4447957a825031b3faf3b5bc2013afe35eff492b (diff)
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/net/e1000e')
-rw-r--r--drivers/net/e1000e/e1000.h2
-rw-r--r--drivers/net/e1000e/netdev.c18
2 files changed, 11 insertions, 9 deletions
diff --git a/drivers/net/e1000e/e1000.h b/drivers/net/e1000e/e1000.h
index 906c4daaabe..c0b3db40bd7 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 d13760dc27f..8de64ed8762 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;