RFR: 8203410: Zero: Disable jfr feature by default

[Erik Joelsson]

The change makes sense, but I think I would prefer if the conditional 
was based on jvm variant rather than the target cpu, like this:

if ! HOTSPOT_CHECK_JVM_VARIANT(zero); then

/Erik


On 2018-05-18 06:57, Severin Gehwolf wrote:
> Hi,
>
> Currently the jfr (Flight Recorder) feature is being built by default
> for Zero JVMs. However, it's not clear whether there will be jfr
> support for the Zero variant JVM. At this point, when
> StartFlightRecording option is being used for a Zero JVM it
> asserts/crashes. It seems more appropriate to disable the feature for a
> default build and require one to enable the feature explicitly via:
>
> configure --with-jvm-feature=jfr --with-jvm-variants=zero
>
> We can revisit this change of default once there is good Zero+JFR
> support, which currently isn't the case.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8203410
> webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8203410/webrev.01/
>
> Testing: Verified that the StartFlightRecording option is unrecognized
> for a default --with-jvm-variants=zero build.
>
> Thoughts?
>
> Thanks,
> Severin