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netem: markov loss model transition fix

The transition from markov state "3 => lost packets within a burst
period" to "1 => successfully transmitted packets within a gap period"
has no *additional* loss event. The loss already happen for transition
from 1 -> 3, this additional loss will make things go wild.

E.g. transition probabilities:

p13:   10%
p31:  100%

Expected:

Ploss = p13 / (p13 + p31)
Ploss = ~9.09%

... but it isn't. Even worse: we get a double loss - each time.
So simple don't return true to indicate loss, rather break and return
false.

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Stefano Salsano <stefano.salsano@uniroma2.it>
Cc: Fabio Ludovici <fabio.ludovici@yahoo.it>
Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Hagen Paul Pfeifer 11 năm trước cách đây
mục cha
commit
4a3ad7b3ea
1 tập tin đã thay đổi với 0 bổ sung1 xóa
  1. 0 1
      net/sched/sch_netem.c

+ 0 - 1
net/sched/sch_netem.c

@@ -235,7 +235,6 @@ static bool loss_4state(struct netem_sched_data *q)
 			clg->state = 2;
 		else if (clg->a3 < rnd && rnd < clg->a2 + clg->a3) {
 			clg->state = 1;
-			return true;
 		} else if (clg->a2 + clg->a3 < rnd) {
 			clg->state = 3;
 			return true;