RFR(S): 8231949: [PPC64, s390]: Make async profiling more reliable

[Reingruber, Richard]

Hi Martin,

your changes look like an improvement to me.

I wonder if that complexity and risk of crashing for interpreter frames is necessary at all...
Well, maybe if we've got some hot, but not compilable method.
Personally I'd prefer a safe solution. Profiling should _never_ crash the vm.

For instance we could write the currently interpreted method and a recent bcp to the thread.

Richard.  // not yet Reviewer

-----Original Message-----
From: hotspot-runtime-dev <hotspot-runtime-dev-bounces at openjdk.java.net> On Behalf Of Doerr, Martin
Sent: Montag, 7. Oktober 2019 16:57
To: hotspot-runtime-dev at openjdk.java.net; Haug, Gunter <gunter.haug at sap.com>; Schmidt, Lutz <lutz.schmidt at sap.com>; Stuefe, Thomas <thomas.stuefe at sap.com>
Subject: [CAUTION] RFR(S): 8231949: [PPC64, s390]: Make async profiling more reliable

Hi,

I'd like to make pd_get_top_frame_for_profiling more reliable on PPC64 and s390 as we have seen crashes in this function.

See bug for more details:
https://bugs.openjdk.java.net/browse/JDK-8231949

Webrev:
http://cr.openjdk.java.net/~mdoerr/8231949_get_top_frame_for_profiling/webrev.00/

Please review.

Best regards,
Martin