• Eric Dumazet's avatar
    net_sched: remove generic throttled management · 45f50bed
    Eric Dumazet authored
    __QDISC_STATE_THROTTLED bit manipulation is rather expensive
    for HTB and few others.
    
    I already removed it for sch_fq in commit f2600cf0
    ("net: sched: avoid costly atomic operation in fq_dequeue()")
    and so far nobody complained.
    
    When one ore more packets are stuck in one or more throttled
    HTB class, a htb dequeue() performs two atomic operations
    to clear/set __QDISC_STATE_THROTTLED bit, while root qdisc
    lock is held.
    
    Removing this pair of atomic operations bring me a 8 % performance
    increase on 200 TCP_RR tests, in presence of throttled classes.
    
    This patch has no side effect, since nothing actually uses
    disc_is_throttled() anymore.
    Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    45f50bed
sch_netem.c 26.9 KB