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| author | Stephen Hemminger <shemminger@linux-foundation.org> | 2007-11-28 14:50:16 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-01-28 15:04:19 -0800 |
| commit | 5f06eba4dce361bfc077868d044768476b41d698 (patch) | |
| tree | fd3522e31b06bae67609b9088231b82200834316 /drivers/net/sky2.c | |
| parent | f03b865491c2f30f2a4d77cdafc69c978ceb38a0 (diff) | |
| download | blackbird-op-linux-5f06eba4dce361bfc077868d044768476b41d698.tar.gz blackbird-op-linux-5f06eba4dce361bfc077868d044768476b41d698.zip | |
sky2: rx allocation threshold change
When using larger MTU's sky2 driver changes from allocating one
data area, to using multiple pages. The threshold for this was based on
a heuristic where the cost of a single allocation is bigger than one
page. Since the allocator has changed, this heuristic is now incorrect;
instead just make the threshold be when the total size of the allocation
is greater than one page.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers/net/sky2.c')
| -rw-r--r-- | drivers/net/sky2.c | 28 |
1 files changed, 9 insertions, 19 deletions
diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c index 30e567a2d5a1..c177e87182f4 100644 --- a/drivers/net/sky2.c +++ b/drivers/net/sky2.c @@ -1234,7 +1234,7 @@ static int sky2_rx_start(struct sky2_port *sky2) struct sky2_hw *hw = sky2->hw; struct rx_ring_info *re; unsigned rxq = rxqaddr[sky2->port]; - unsigned i, size, space, thresh; + unsigned i, size, thresh; sky2->rx_put = sky2->rx_next = 0; sky2_qset(hw, rxq); @@ -1261,28 +1261,18 @@ static int sky2_rx_start(struct sky2_port *sky2) /* Stopping point for hardware truncation */ thresh = (size - 8) / sizeof(u32); - /* Account for overhead of skb - to avoid order > 0 allocation */ - space = SKB_DATA_ALIGN(size) + NET_SKB_PAD - + sizeof(struct skb_shared_info); - - sky2->rx_nfrags = space >> PAGE_SHIFT; + sky2->rx_nfrags = size >> PAGE_SHIFT; BUG_ON(sky2->rx_nfrags > ARRAY_SIZE(re->frag_addr)); - if (sky2->rx_nfrags != 0) { - /* Compute residue after pages */ - space = sky2->rx_nfrags << PAGE_SHIFT; + /* Compute residue after pages */ + size -= sky2->rx_nfrags << PAGE_SHIFT; - if (space < size) - size -= space; - else - size = 0; + /* Optimize to handle small packets and headers */ + if (size < copybreak) + size = copybreak; + if (size < ETH_HLEN) + size = ETH_HLEN; - /* Optimize to handle small packets and headers */ - if (size < copybreak) - size = copybreak; - if (size < ETH_HLEN) - size = ETH_HLEN; - } sky2->rx_data_size = size; /* Fill Rx ring */ |
