From: Daniel Borkmann <daniel@iogearbox•net>
To: Jesper Dangaard Brouer <brouer@redhat•com>
Cc: netdev@vger•kernel.org, John Fastabend <john.fastabend@gmail•com>
Subject: Re: [PATCH net-next 5/5] xdp: get tracepoints xdp_exception and xdp_redirect in sync
Date: Wed, 23 Aug 2017 10:54:16 +0200 [thread overview]
Message-ID: <599D42B8.6040200@iogearbox.net> (raw)
In-Reply-To: <20170823094118.38010b86@redhat.com>
On 08/23/2017 09:41 AM, Jesper Dangaard Brouer wrote:
> On Tue, 22 Aug 2017 23:30:21 +0200
> Daniel Borkmann <daniel@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 <brouer@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.
Yeah, makes sense, right now we cannot differentiate between that.
> I'll code this up and submit at V2.
Thanks!
next prev parent reply other threads:[~2017-08-23 8:54 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-22 20:47 [PATCH net-next 0/5] xdp: more work on xdp tracepoints Jesper Dangaard Brouer
2017-08-22 20:47 ` [PATCH net-next 1/5] xdp: remove bpf_warn_invalid_xdp_redirect Jesper Dangaard Brouer
2017-08-22 21:19 ` Daniel Borkmann
2017-08-22 20:47 ` [PATCH net-next 2/5] xdp: make generic xdp redirect use tracepoint trace_xdp_redirect Jesper Dangaard Brouer
2017-08-22 21:21 ` Daniel Borkmann
2017-08-22 20:47 ` [PATCH net-next 3/5] ixgbe: use return codes from ndo_xdp_xmit that are distinguishable Jesper Dangaard Brouer
2017-08-22 21:21 ` Daniel Borkmann
2017-08-22 20:47 ` [PATCH net-next 4/5] xdp: remove net_device names from xdp_redirect tracepoint Jesper Dangaard Brouer
2017-08-22 21:23 ` Daniel Borkmann
2017-08-22 20:47 ` [PATCH net-next 5/5] xdp: get tracepoints xdp_exception and xdp_redirect in sync Jesper Dangaard Brouer
2017-08-22 21:30 ` Daniel Borkmann
2017-08-23 7:41 ` Jesper Dangaard Brouer
2017-08-23 8:54 ` Daniel Borkmann [this message]
2017-08-23 10:15 ` [V2 PATCH net-next 0/5] xdp: more work on xdp tracepoints Jesper Dangaard Brouer
2017-08-23 10:15 ` [V2 PATCH net-next 1/5] xdp: remove bpf_warn_invalid_xdp_redirect Jesper Dangaard Brouer
2017-08-23 10:15 ` [V2 PATCH net-next 2/5] xdp: make generic xdp redirect use tracepoint trace_xdp_redirect Jesper Dangaard Brouer
2017-08-23 10:15 ` [V2 PATCH net-next 3/5] ixgbe: use return codes from ndo_xdp_xmit that are distinguishable Jesper Dangaard Brouer
2017-08-23 10:15 ` [V2 PATCH net-next 4/5] xdp: remove net_device names from xdp_redirect tracepoint Jesper Dangaard Brouer
2017-08-23 10:58 ` Daniel Borkmann
2017-08-23 10:15 ` [V2 PATCH net-next 5/5] xdp: get tracepoints xdp_exception and xdp_redirect in sync Jesper Dangaard Brouer
2017-08-23 10:59 ` Daniel Borkmann
2017-08-23 11:16 ` [V2 PATCH net-next 0/5] xdp: more work on xdp tracepoints Jesper Dangaard Brouer
2017-08-24 0:07 ` David Miller
2017-08-24 10:32 ` [V3 " Jesper Dangaard Brouer
2017-08-24 10:33 ` [V3 PATCH net-next 1/5] xdp: remove bpf_warn_invalid_xdp_redirect Jesper Dangaard Brouer
2017-08-24 10:33 ` [V3 PATCH net-next 2/5] xdp: make generic xdp redirect use tracepoint trace_xdp_redirect Jesper Dangaard Brouer
2017-08-24 10:33 ` [V3 PATCH net-next 3/5] ixgbe: use return codes from ndo_xdp_xmit that are distinguishable Jesper Dangaard Brouer
2017-08-24 10:33 ` [V3 PATCH net-next 4/5] xdp: remove net_device names from xdp_redirect tracepoint Jesper Dangaard Brouer
2017-08-24 10:33 ` [V3 PATCH net-next 5/5] xdp: get tracepoints xdp_exception and xdp_redirect in sync Jesper Dangaard Brouer
2017-08-24 14:46 ` [V3 PATCH net-next 0/5] xdp: more work on xdp tracepoints John Fastabend
2017-08-24 19:00 ` David Miller
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