On Tue, Mar 26, 2024 at 6:29 PM Paolo Abeni [off-list ref] wrote:

On Tue, 2024-03-26 at 12:14 +0800, Jason Xing wrote:

quoted

On Mon, Mar 25, 2024 at 11:43 AM Jason Xing [off-list ref] wrote:

quoted

From: Jason Xing <kernelxing@tencent.com>

Using the macro for other tracepoints use to be more concise.
No functional change.

Jason Xing (3):
  trace: move to TP_STORE_ADDRS related macro to net_probe_common.h
  trace: use TP_STORE_ADDRS() macro in inet_sk_error_report()
  trace: use TP_STORE_ADDRS() macro in inet_sock_set_state()

 include/trace/events/net_probe_common.h | 29 ++++++++++++++++++++
 include/trace/events/sock.h             | 35 ++++---------------------

I just noticed that some trace files in include/trace directory (like
net_probe_common.h, sock.h, skb.h, net.h, sock.h, udp.h, sctp.h,
qdisc.h, neigh.h, napi.h, icmp.h, ...) are not owned by networking
folks while some files (like tcp.h) have been maintained by specific
maintainers/experts (like Eric) because they belong to one specific
area. I wonder if we can get more networking guys involved in net
tracing.

I'm not sure if 1) we can put those files into the "NETWORKING
[GENERAL]" category, or 2) we can create a new category to include
them all.

I think all the file you mentioned are not under networking because of
MAINTAINER file inaccuracy, and we could move there them accordingly.

Yes, they are not under the networking category currently. So how
could we move them? The MAINTAINER file doesn't have all the specific
categories which are suitable for each of the trace files.

quoted

I know people start using BPF to trace them all instead, but I can see
some good advantages of those hooks implemented in the kernel, say:
1) help those machines which are not easy to use BPF tools.
2) insert the tracepoint in the middle of some functions which cannot
be replaced by bpf kprobe.
3) if we have enough tracepoints, we can generate a timeline to
know/detect which flow/skb spends unexpected time at which point.
...
We can do many things in this area, I think :)

What do you think about this, Jakub, Paolo, Eric ?

I agree tracepoints are useful, but I think the general agreement is
that they are the 'old way', we should try to avoid their
proliferation.

Well, it's a pity that it seems that we are about to abandon this
method but it's not that friendly to the users who are unable to
deploy BPF... Well, I came up with more ideas about how to improve the
trace function in recent days. The motivation of doing this is that I
encountered some issues which could be traced/diagnosed by using trace
effortlessly without writing some bpftrace codes again and again. The
status of trace seems not active but many people are still using it, I
believe.

Thanks,
Jason

Cheers,

Paolo