gred: support TCA_GRED_MAX_P attribute

TCA_GRED_MAX_P permits to express high resolution probabilities.

New output (on 3.3+ kernel) :

disc gred 9442: root refcnt 17
 DP:0 (prio 1) Average Queue 0b Measured Queue 0b
	 Packet drops: 0 (forced 0 early 0)
	 Packet totals: 20 (bytes 2584)
 limit 31460b min 3000b max 9000b ewma 5 probability 0.05 Scell_log 15

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
1 file changed