• Jesper Dangaard Brouer's avatar
    qdisc: add tracepoint qdisc:qdisc_dequeue for dequeued SKBs · e543002f
    Jesper Dangaard Brouer authored
    The main purpose of this tracepoint is to monitor bulk dequeue
    in the network qdisc layer, as it cannot be deducted from the
    existing qdisc stats.
    
    The txq_state can be used for determining the reason for zero packet
    dequeues, see enum netdev_queue_state_t.
    
    Notice all packets doesn't necessary activate this tracepoint. As
    qdiscs with flag TCQ_F_CAN_BYPASS, can directly invoke
    sch_direct_xmit() when qdisc_qlen is zero.
    
    Remember that perf record supports filters like:
    
     perf record -e qdisc:qdisc_dequeue \
      --filter 'ifindex == 4 && (packets > 1 || txq_state > 0)'
    Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    e543002f
qdisc.h 1.37 KB