• Eric Dumazet's avatar
    sch_sfq: revert dont put new flow at the end of flows · cc34eb67
    Eric Dumazet authored
    This reverts commit d47a0ac7 (sch_sfq: dont put new flow at the end of
    As Jesper found out, patch sounded great but has bad side effects.
    In stress situation, pushing new flows in front of the queue can prevent
    old flows doing any progress. Packets can stay in SFQ queue for
    unlimited amount of time.
    It's possible to add heuristics to limit this problem, but this would
    add complexity outside of SFQ scope.
    A more sensible answer to Dave Taht concerns (who reported the issued I
    tried to solve in original commit) is probably to use a qdisc hierarchy
    so that high prio packets dont enter a potentially crowded SFQ qdisc.
    Reported-by: default avatarJesper Dangaard Brouer <jdb@comx.dk>
    Cc: Dave Taht <dave.taht@gmail.com>
    Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
sch_sfq.c 22.4 KB