Re: [PATCH] sched/tracing: append prev_state to tp args instead

[Delyan Kratunov]

On Fri, 2022-04-22 at 13:09 +0200, Peter Zijlstra wrote:
> And on the other hand; those users need to be fixed anyway, right?
> Accessing prev->__state is equally broken.

The users that access prev->__state would most likely have to be fixed, for sure.

However, not all users access prev->__state. `offcputime` for example just takes a
stack trace and associates it with the switched out task. This kind of user
would continue working with the proposed patch.

> If bpf wants to ride on them, it needs to suffer the pain of doing so.

Sure, I'm just advocating for a fairly trivial patch to avoid some of the suffering,
hopefully without being a burden to development. If that's not the case, then it's a
clear no-go.