On Tue, 22 Aug 2017 23:30:21 +0200 Daniel Borkmann <dan...@iogearbox.net> wrote:
> On 08/22/2017 10:47 PM, Jesper Dangaard Brouer wrote: > > Remove the net_device string name from the xdp_exception tracepoint, > > like the xdp_redirect tracepoint. > > > > Align the TP_STRUCT to have common entries between these two > > tracepoint. > > > > Signed-off-by: Jesper Dangaard Brouer <bro...@redhat.com> > > --- > > include/trace/events/xdp.h | 24 ++++++++++++------------ > > 1 file changed, 12 insertions(+), 12 deletions(-) > > > > diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h > > index 7511bed80558..6495b0d9d5c7 100644 > > --- a/include/trace/events/xdp.h > > +++ b/include/trace/events/xdp.h > > @@ -31,22 +31,22 @@ TRACE_EVENT(xdp_exception, > > TP_ARGS(dev, xdp, act), > > > > TP_STRUCT__entry( > > - __string(name, dev->name) > > __array(u8, prog_tag, 8) > > __field(u32, act) > > + __field(int, ifindex) > > ), > > > > 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, dev->name); > > - __entry->act = act; > > + __entry->act = act; > > + __entry->ifindex = dev->ifindex; > > ), > > > [...] > > TRACE_EVENT(xdp_redirect, > > @@ -57,26 +57,26 @@ TRACE_EVENT(xdp_redirect, > > TP_ARGS(from_index, to_index, xdp, act, err), > > > > TP_STRUCT__entry( > > - __field(int, from_index) > > - __field(int, to_index) > > __array(u8, prog_tag, 8) > > __field(u32, act) > > + __field(int, from_index) > > + __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)); > > + __entry->act = act; > > __entry->from_index = from_index; > > __entry->to_index = to_index; > > - __entry->act = act; > > If you already get them in sync, could you also make it consistent > that for both tracepoints in TP_ARGS() we use either ifindex > directly or device pointer and extract it from TP_fast_assign(). > Right now, it's mixed. I did this because, in the (bpf_redirect)_map case, I was hoping that "from_index" could be come the index from the map. Looking closer at the devmap design, I cannot see how we can ever know what (the bpf_prog thinks) is the corresponding map-ingress/from_index. Based on that, I think we can/should use the device pointer as arg (as you suggested). And then rename "from_index" to "ifindex", where ifindex is the XDP ifindex the xdp_buff arrived on. I guess we can keep the "to_index". We also need to extend the tracepoint args with a "map", to let the trace user tell whether the "to_index" is an ifindex or a map-index. I'll code this up and submit at V2. -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
