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

[Haug, Gunter]

Hi Richard,

That's a really good idea, not only for PPC but even more so for s390. On PPC we always have a valid SP, which I think doesn't hold on s390.
Otherwise +1 for Martin's change.

Gunter // not a Reviewer

On 11.10.19, 14:07, "Reingruber, Richard" <richard.reingruber at sap.com> wrote:

    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