On Sun, 2013-07-28 at 21:22 +0100, Ben Hutchings wrote:

Since we know lengths > 4K work, perhaps it would be worth testing with
the fragment cache size reduced to 16K?  The driver would never
previously have used RX buffers crossing 16K boundaries, except if SLOB
was used (and that's an unlikely combination).

Sure, please note the following maths :

NET_SKB_PAD + 1536 + sizeof(struct skb_shared_info) = 1920

16384/1920 = 8

32768/1920 = 17

I don't think atl1c is used in any critical host (given it doesn't even
provide RX checksums and GRO ...), so I will provide a patch doing mere
page allocations.