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xdp: remove net_device names from xdp_redirect tracepoint

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There is too much overhead in the current trace_xdp_redirect
tracepoint as it does strcpy and strlen on the net_device names.

Besides, exposing the ifindex/index is actually the information that
is needed in the tracepoint to diagnose issues.  When a lookup fails
(either ifindex or devmap index) then there is a need for saying which
to_index that have issues.

V2: Adjust args to be aligned with trace_xdp_exception.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jesper Dangaard Brouer 2017-08-24 12:33:18 +02:00 committed by David S. Miller
parent 2886447dc5
commit a873585587
2 changed files with 15 additions and 15 deletions
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24
include/trace/events/xdp.h
View File

@ -51,33 +51,33 @@ TRACE_EVENT(xdp_exception,
TRACE_EVENT(xdp_redirect,
TP_PROTO(const struct net_device *from,
const struct net_device *to,
const struct bpf_prog *xdp, u32 act, int err),
TP_PROTO(const struct net_device *dev,
const struct bpf_prog *xdp, u32 act,
int to_index, int err),
TP_ARGS(from, to, xdp, act, err),
TP_ARGS(dev, xdp, act, to_index, err),
TP_STRUCT__entry(
__string(name_from, from->name)
__string(name_to, to->name)
__array(u8, prog_tag, 8)
__field(u32, act)
__field(int, ifindex)
__field(int, to_index)
__field(int, err)
),
TP_fast_assign(
BUILD_BUG_ON(sizeof(__entry->prog_tag) != sizeof(xdp->tag));
memcpy(__entry->prog_tag, xdp->tag, sizeof(xdp->tag));
__assign_str(name_from, from->name);
__assign_str(name_to, to->name);
__entry->act = act;
__entry->err = err;
__entry->act = act;
__entry->ifindex = dev->ifindex;
__entry->to_index = to_index;
__entry->err = err;
),
TP_printk("prog=%s from=%s to=%s action=%s err=%d",
TP_printk("prog=%s action=%s ifindex=%d to_index=%d err=%d",
__print_hex_str(__entry->prog_tag, 8),
__get_str(name_from), __get_str(name_to),
__print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
__entry->ifindex, __entry->to_index,
__entry->err)
);
#endif /* _TRACE_XDP_H */

6
net/core/filter.c
View File

@ -2524,7 +2524,7 @@ static int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp,
if (likely(!err))
ri->map_to_flush = map;
out:
trace_xdp_redirect(dev, fwd, xdp_prog, XDP_REDIRECT, err);
trace_xdp_redirect(dev, xdp_prog, XDP_REDIRECT, index, err);
return err;
}
@ -2548,7 +2548,7 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
err = __bpf_tx_xdp(fwd, NULL, xdp, 0);
out:
trace_xdp_redirect(dev, fwd, xdp_prog, XDP_REDIRECT, err);
trace_xdp_redirect(dev, xdp_prog, XDP_REDIRECT, index, err);
return err;
}
EXPORT_SYMBOL_GPL(xdp_do_redirect);
@ -2582,7 +2582,7 @@ int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
skb->dev = fwd;
out:
trace_xdp_redirect(dev, fwd, xdp_prog, XDP_REDIRECT, err);
trace_xdp_redirect(dev, xdp_prog, XDP_REDIRECT, index, err);
return err;
}
EXPORT_SYMBOL_GPL(xdp_do_generic_redirect);