RFR(M): JDK-8163011: AArch64: NMT detail stack trace cleanup

[Thomas Stüfe]

Hi Dmitry,

On Thu, Aug 31, 2017 at 9:49 AM, dmitry.samersov <
dmitry.samersoff at bell-sw.com> wrote:

> Everybody,
>
> Please review:
>
>     http://cr.openjdk.java.net/~dsamersoff/JDK-8163011/webrev.05/
>
>     I would propose different approach to fix JDK-8133740
> platform-independent way: record all frames but strip unnecessary
> NMT-internal ones on printing.
>
> This approach is safe (we don't depend to compiler inlining and we never
> strip non-NMT frames) and platform independent, but cost us some extra
> memory.
>
> -Dmitry
>
>
>
This looks good, I like it. Code is easier to read now and less vulnerable
to compiler decisions.

Small nits:

should_skip_frame() - as this is an implementation detail for the print
function, could we not just move it into the print function, or at least
into nativeCallStack.cpp ?

---

for (int index = 0; index < indent; index ++) out->print(" ");

Could this be done with

out->print("%*c", indent, ' ');

instead?

---

The changes in os::_get_previous_fp() for the four platforms affect
os::get_native_stack() and method handle tracing
(trace_method_handle_stub). The former may now, for the assert case, print
more frames. The latter should, in theory, not change behavior at all. But
this is from reading the code, it might be good to test this.

Kind Regards, Thomas