alignment faults in 3.6

On Thu, 2012-10-11 at 12:49 +0200, Eric Dumazet wrote:

So if you have an alignment fault, thats because IP header is not
aligned on 4 bytes ?

If so a driver is buggy and must be fixed.

So a driver that does not align the ip header is buggy ?

I always thought it was ok not to do so (with a potential performance
penalty).

I have some MIPS hardware that is not able to DMA on anything but 32bits
aligned addresses (bcm63xx). I tried once to add a memcpy instead of
taking unaligned faults and the result was *much slower* on a ipv4
forwarding test (which is what the hardware is used for).

-- 
Maxime