RFR(XS): 8221121: applications/microbenchmarks are encountering crashes in tier5

[Markus Gronlund]

Thanks Erik,

Can I please have yet another reviewer for this change?

Thanks in advance
Markus 

-----Original Message-----
From: Erik Gahlin 
Sent: den 26 april 2019 20:07
To: Markus Gronlund <markus.gronlund at oracle.com>; Hotspot dev runtime <hotspot-runtime-dev at openjdk.java.net>; hotspot-jfr-dev at openjdk.java.net
Subject: Re: RFR(XS): 8221121: applications/microbenchmarks are encountering crashes in tier5

Looks good.

Erik

> Greetings,
>
> Please review this small patch to address the following:
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8221121
> Webrev: http://cr.openjdk.java.net/~mgronlun/8221121/webrev01/
>
> Description:
>
> The applications/microbenchmarks added to tier5 are failing in some instances (debug builds), with, as an example, the following trace:
>
> #
> # A fatal error has been detected by the Java Runtime Environment:
> #
> # Internal Error 
> (/scratch/opt/mach5/mesos/work_dir/slaves/2dd962d0-8988-479b-a804-57ab
> 764ada59-S77631/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/e
> xecutors/d8f4cb38-0dec-4477-a89a-f62853433c56/runs/cb3f55fa-9e13-481c-
> a7d6-9f33d2b8b457/workspace/open/src/hotspot/share/jfr/recorder/storag
> e/jfrMemorySpace.inline.hpp:85), pid=5748, tid=5770 # 
> assert(t->identity() == __null) failed: invariant
>
> This occurred when JFR was running with the in-memory configuration where buffers are reused FIFO-style.
> In the implementation, an "age node" will manage a full buffer for its reclamation, and age nodes provides for a linked "full" (fifo) list.
>
> Issue:
> The age node was not expected to retain an identity after being added to the full list, where the assertion fired during the subsequent discard-reuse processing step.
> This situation only manifests with running JFR in-memory configurations and using debug builds.
>
> Fix is to release the age node before insertion onto full list.
>
> Thanks
> Markus