mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-05 10:29:37 +00:00
![Jesper Dangaard Brouer](/assets/img/avatar_default.png)
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: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
50 lines
1.4 KiB
C
50 lines
1.4 KiB
C
#undef TRACE_SYSTEM
|
|
#define TRACE_SYSTEM qdisc
|
|
|
|
#if !defined(_TRACE_QDISC_H) || defined(TRACE_HEADER_MULTI_READ)
|
|
#define _TRACE_QDISC_H_
|
|
|
|
#include <linux/skbuff.h>
|
|
#include <linux/netdevice.h>
|
|
#include <linux/tracepoint.h>
|
|
#include <linux/ftrace.h>
|
|
|
|
TRACE_EVENT(qdisc_dequeue,
|
|
|
|
TP_PROTO(struct Qdisc *qdisc, const struct netdev_queue *txq,
|
|
int packets, struct sk_buff *skb),
|
|
|
|
TP_ARGS(qdisc, txq, packets, skb),
|
|
|
|
TP_STRUCT__entry(
|
|
__field( struct Qdisc *, qdisc )
|
|
__field(const struct netdev_queue *, txq )
|
|
__field( int, packets )
|
|
__field( void *, skbaddr )
|
|
__field( int, ifindex )
|
|
__field( u32, handle )
|
|
__field( u32, parent )
|
|
__field( unsigned long, txq_state)
|
|
),
|
|
|
|
/* skb==NULL indicate packets dequeued was 0, even when packets==1 */
|
|
TP_fast_assign(
|
|
__entry->qdisc = qdisc;
|
|
__entry->txq = txq;
|
|
__entry->packets = skb ? packets : 0;
|
|
__entry->skbaddr = skb;
|
|
__entry->ifindex = txq->dev ? txq->dev->ifindex : 0;
|
|
__entry->handle = qdisc->handle;
|
|
__entry->parent = qdisc->parent;
|
|
__entry->txq_state = txq->state;
|
|
),
|
|
|
|
TP_printk("dequeue ifindex=%d qdisc handle=0x%X parent=0x%X txq_state=0x%lX packets=%d skbaddr=%p",
|
|
__entry->ifindex, __entry->handle, __entry->parent,
|
|
__entry->txq_state, __entry->packets, __entry->skbaddr )
|
|
);
|
|
|
|
#endif /* _TRACE_QDISC_H_ */
|
|
|
|
/* This part must be outside protection */
|
|
#include <trace/define_trace.h>
|