Re: [PATCH v3] tracing: Guard __DECLARE_TRACE() use of __DO_TRACE_CALL() with SRCU-fast

[Steven Rostedt]

On Fri, 12 Dec 2025 23:19:41 -0500
Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote:

> Here is one additional thing to keep in mind: although
> SRCU-fast is probably quite fast (as the name implies),
> last time I tried using migrate disable in a fast path
> I was surprised to see verbosity of the generated assembly,
> and how slow it was compared to preempt disable.
> 
> So before using migrate disable on a fast path, at least on
> non-preempt-RT configs, we should carefully consider the
> performance impact of migrate disable.

Right, which is another reason I'm keeping that part of the patch as-is.

-- Steve