Re: [PATCH net-next] trace: tcp: Add tracepoint for tcp_sendmsg()

Breno Leitao
2025-02-26T18:18:34Z

Hello David,

On Wed, Feb 26, 2025 at 10:12:08AM -0700, David Ahern wrote:
> On 2/26/25 9:10 AM, Breno Leitao wrote:
> >> Also, if a tracepoint is added, inside of tcp_sendmsg_locked would cover
> >> more use cases (see kernel references to it).
> >
> > Agree, this seems to provide more useful information
> >
> >> We have a patch for a couple years now with a tracepoint inside the
> >
> > Sorry, where do you have this patch? is it downstream?
>
> company tree. Attached. Where to put tracepoints and what arguments to
> supply so that it is beneficial to multiple users is always a touchy
> subject :-)

Thanks. I would like to state that this would be useful for Meta as
well.

Right now, we (Meta) are using nasty `noinline` attribute in
tcp_sendmsg() in order to make the API stable, and this tracepoint would
solve this problem avoiding the `noinline` hack. So, at least two type
of users would benefit from it.

> so I have not tried to push the patch out. sock arg should
> be added to it for example.

True, if it becomes a tracepoint instead of a rawtracepoint, the sock
arg might be useful.

How would you recommend me proceeding in this case?

Thanks
--breno