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>
diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index 30e567a..c177e87 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -1234,7 +1234,7 @@
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 @@
/* 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 */