----- On Nov 17, 2020, at 5:16 PM, rostedt rostedt@goodmis.org wrote:

On Tue, 17 Nov 2020 16:22:23 -0500 (EST)
Mathieu Desnoyers [off-list ref] wrote:

quoted

If we don't call the stub, then there is no point in having the stub at
all, and we should just compare to a constant value, e.g. 0x1UL. As far
as I can recall, comparing with a small immediate constant is more efficient
than comparing with a loaded value on many architectures.

Why 0x1UL, and not just set it to NULL.

	do {							\
		it_func = (it_func_ptr)->func;			\
		__data = (it_func_ptr)->data;			\
		if (likely(it_func))				\
			((void(*)(void *, proto))(it_func))(__data, args); \
	} while ((++it_func_ptr)->func);

Because of this end-of-loop condition ^
which is also testing for a NULL func. So if we reach a stub, we end up stopping
iteration and not firing the following tracepoint probes.

Thanks,

Mathieu

-- Steve

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com