Re: [PATCH v2 15/18] rtla: Make stop_tracing variable volatile

[Crystal Wood]

On Tue, 2026-01-06 at 11:05 -0500, Steven Rostedt wrote:
> On Tue,  6 Jan 2026 08:49:51 -0300
> Wander Lairson Costa <wander@xxxxxxxxxx> wrote:
> 
> > Add the volatile qualifier to stop_tracing in both common.c and
> > common.h to ensure all accesses to this variable bypass compiler
> > optimizations and read directly from memory. This guarantees that
> > when the signal handler sets stop_tracing, the change is immediately
> > visible to the main program loop, preventing potential hangs or
> > delayed shutdown when termination signals are received.
> 
> In the kernel, this is handled via the READ_ONCE() macro. Perhaps rtla
> should implement that too.

Or just get it from tools/include/linux/compiler.h.  No need to reinvent
the wheel (even though several other tools do).

That said, signal safety is a pretty routine use for volatile.

-Crystal