diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2009-06-05 06:04:16 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-06-08 09:21:48 +0200 |
| commit | 042a53a9e437feaf2230dd2cadcecfae9c7bfe05 (patch) | |
| tree | ae9078f61e390a3014aecb3fe80d3438ab25ee51 /drivers/net/bnx2.c | |
| parent | net: num_dma_maps is not used (diff) | |
| download | linux-042a53a9e437feaf2230dd2cadcecfae9c7bfe05.tar.xz linux-042a53a9e437feaf2230dd2cadcecfae9c7bfe05.zip | |
net: skb_shared_info optimization
skb_dma_unmap() is quite expensive for small packets,
because we use two different cache lines from skb_shared_info.
One to access nr_frags, one to access dma_maps[0]
Instead of dma_maps being an array of MAX_SKB_FRAGS + 1 elements,
let dma_head alone in a new dma_head field, close to nr_frags,
to reduce cache lines misses.
Tested on my dev machine (bnx2 & tg3 adapters), nice speedup !
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/bnx2.c')
| -rw-r--r-- | drivers/net/bnx2.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c index f53017250e09..391d2d47089c 100644 --- a/drivers/net/bnx2.c +++ b/drivers/net/bnx2.c @@ -5487,7 +5487,7 @@ bnx2_run_loopback(struct bnx2 *bp, int loopback_mode) dev_kfree_skb(skb); return -EIO; } - map = skb_shinfo(skb)->dma_maps[0]; + map = skb_shinfo(skb)->dma_head; REG_WR(bp, BNX2_HC_COMMAND, bp->hc_cmd | BNX2_HC_COMMAND_COAL_NOW_WO_INT); @@ -6167,7 +6167,7 @@ bnx2_start_xmit(struct sk_buff *skb, struct net_device *dev) } sp = skb_shinfo(skb); - mapping = sp->dma_maps[0]; + mapping = sp->dma_head; tx_buf = &txr->tx_buf_ring[ring_prod]; tx_buf->skb = skb; @@ -6191,7 +6191,7 @@ bnx2_start_xmit(struct sk_buff *skb, struct net_device *dev) txbd = &txr->tx_desc_ring[ring_prod]; len = frag->size; - mapping = sp->dma_maps[i + 1]; + mapping = sp->dma_maps[i]; txbd->tx_bd_haddr_hi = (u64) mapping >> 32; txbd->tx_bd_haddr_lo = (u64) mapping & 0xffffffff; |