• Hagen Paul Pfeifer's avatar
    netem: markov loss model transition fix · 4a3ad7b3
    Hagen Paul Pfeifer authored
    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: default avatarHagen 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: default avatarHagen Paul Pfeifer <hagen@jauu.net>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    4a3ad7b3
sch_netem.c 25.7 KB