TPACKET_ALIGNMENT
#define TPACKET_ALIGN(x) (((x)+TPACKET_ALIGNMENT-1)&~(TPACKET_ALIGNMENT-1))
if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
# define __aligned_tpacket __attribute__((aligned(TPACKET_ALIGNMENT)))
ring->req.tp_frame_size = TPACKET_ALIGNMENT << 7;
ring->req3.tp_frame_size = TPACKET_ALIGNMENT << 7;