Re: [PATCH 3/6] tracing: Wrap section comparison in tracer_alloc_buffers with COMPARE_SECTIONS

Steven Rostedt
2020-02-19T19:43:33Z

On Wed, 19 Feb 2020 12:22:49 -0700
Nathan Chancellor <natechancellor@gmail.com> wrote:

> Yes, thank you for the analysis and further discussion! I have done some
> rudimentary printk debugging in QEMU and it looks like these are produce
> the same value:
>
> __stop___trace_bprintk_fmt
> &__stop___trace_bprintk_fmt
> &__start___trace_bprintk_fmt[0]
>
> as well as
>
> __stop___trace_bprintk_fmt != __start___trace_bprintk_fmt
> &__stop___trace_bprintk_fmt != &__start___trace_bprintk_fmt
> &__stop___trace_bprintk_fmt[0] != &__start___trace_bprintk_fmt[0]
>
> I'll use the second one once I confirm this is true in all callspots
> with both Clang and GCC, since it looks cleaner. Let me know if there
> are any objections to that.

Myself and I'm sure others would be fine with this approach as it is
still readable. I was just against the encapsulating the logic in a
strange macro that killed readability.

I haven't looked at the resulting assembly from these, and will
currently take your word for it ;-) Of course, I will thoroughly test
any patches to this code to make sure it does not hurt functionality.

-- Steve