Re: [PATCH net-next] udp: Add tracepoint for udp_sendmsg()

Paolo Abeni
2025-04-17T13:17:16Z

On 4/17/25 1:34 PM, Breno Leitao wrote:
> On Thu, Apr 17, 2025 at 08:57:24AM +0200, Paolo Abeni wrote:
>> On 4/16/25 9:23 PM, Breno Leitao wrote:
>>> Add a lightweight tracepoint to monitor UDP send message operations,
>>> similar to the recently introduced tcp_sendmsg_locked() trace event in
>>> commit 0f08335ade712 ("trace: tcp: Add tracepoint for
>>> tcp_sendmsg_locked()")
>>
>> Why is it needed? what would add on top of a plain perf probe, which
>> will be always available for such function with such argument, as the
>> function can't be inlined?
>
> Why this function can't be inlined?

Because the kernel need to be able find a pointer to it:

.sendmsg = udp_sendmsg,

I'll be really curious to learn how the compiler could inline that.

/P