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    mac80211: skip netdev queue control with software queuing · 80a83cfc
    Michal Kazior 提交于
    Qdiscs are designed with no regard to 802.11
    aggregation requirements and hand out
    packet-by-packet with no guarantee they are
    destined to the same tid. This does more bad than
    good no matter how fairly a given qdisc may behave
    on an ethernet interface.
    
    Software queuing used per-AC netdev subqueue
    congestion control whenever a global AC limit was
    hit. This meant in practice a single station or
    tid queue could starve others rather easily. This
    could resonate with qdiscs in a bad way or could
    just end up with poor aggregation performance.
    Increasing the AC limit would increase induced
    latency which is also bad.
    
    Disabling qdiscs by default and performing
    taildrop instead of netdev subqueue congestion
    control on the other hand makes it possible for
    tid queues to fill up "in the meantime" while
    preventing stations starving each other.
    
    This increases aggregation opportunities and
    should allow software queuing based drivers
    achieve better performance by utilizing airtime
    more efficiently with big aggregates.
    Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
    Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
    80a83cfc
util.c 88.3 KB