RFR(S) 8074312: Enable hotspot builds on 4.x Linux kernels

[David Holmes]

Hi Severin,

On 6/03/2015 2:27 AM, Severin Gehwolf wrote:
> Hi,
>
> Could someone please review the following one-liner to the hotspot build
> files. This prevents someone from building on 4.x Linux kernels such as
> F22, which will become available in May 2015[1].
>
> Currently, a JDK 9 build fails for me with:
>> &2 echo "*** This OS is not supported:" `uname -a`; exit 1;
> ++ uname -a
> + echo '*** This OS is not supported:' Linux f22 4.0.0-0.rc1.git0.1.fc22.x86_64 '#1' SMP Mon Feb 23 21:15:25 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
> *** This OS is not supported: Linux f22 4.0.0-0.rc1.git0.1.fc22.x86_64 #1 SMP Mon Feb 23 21:15:25 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
> + exit 1
>
> The fix is to add 4 to the list of Linux kernels, similar to what was
> done for 3.x kernels in JDK-7072341.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8074312
> webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8074312/webrev.00/
>
> I'd also please need a sponsor for this change.

The whole purpose of those version checks is to ensure we know there is 
a reasonable level of support for a platform before we enable it - 
anyone can make the change locally to try for themselves (and deal with 
the consequences). Otherwise we may as well just remove the version checks.

So I can sponsor this change for you assuming that everything does 
indeed build and run fine on the Linux 4 kernel. Also it seems Fedora22 
will have gcc 5 so do we need build changes to support that as well?

Are there any major new or changed features in the linux 4 kernel that 
may impact the JVM?

Thanks,
David


> Thanks,
> Severin
>
> [1] http://fedoraproject.org/wiki/Releases/22/Schedule
>