Configure: Does enabling graal automatically disable cmsgc?

[Lindenmaier, Goetz]

Hi Magnus,

Ok, I understand, isGraalEnabled is a runtime check, not a 
check what was set at compile time of the JVM. And the 
two tier-4 comilers can be there both.
So I understand the check in the test.

Thanks,
  Goetz

> -----Original Message-----
> From: Magnus Ihse Bursie <magnus.ihse.bursie at oracle.com>
> Sent: Freitag, 31. August 2018 12:07
> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; hotspot compiler
> <hotspot-compiler-dev at openjdk.java.net>; build-dev (build-
> dev at openjdk.java.net) <build-dev at openjdk.java.net>
> Subject: Re: Configure: Does enabling graal automatically disable cmsgc?
> 
> On 2018-08-31 11:39, Lindenmaier, Goetz wrote:
> > Hi,
> >
> > I'm just fixing
> jtreg/runtime/appcds/sharedStrings/IncompatibleOptions.java
> >
> > It is not checking correctly whether ZGC is enabled.
> >
> > I found this code in the test:
> > if (!Compiler.isGraalEnabled()) { // Graal does not support CMS
> >        testExec(8, "-XX:+UseConcMarkSweepGC", "", "", false);
> > }
> >
> > I think this should test for GC.CMS.isSupported(). I would like to
> > fix this, too.
> > But this would require that configuring with graal disables cmsgc.
> > (Which seems to be what is desired given the comment above.)
> > Is this the case?
> 
> Maybe I'm confused here, but are you not mixing up configure options and
> run-time options? Both graal and CMS require run-time options to be
> enabled, right? So it's an error to enable both of them. But that does
> not prohibit you to build a JVM that has support for both Graal and CMS
> (as long as you only enable at most one of them at a time).
> 
> /Magnus