I am just wondering, what are the practical reasons for including two
libjvms in the same JDK?
We had server/client VMs in the past so we can use the same JDK for
running "throughput" jobs vs "desktop/interactive" jobs. But that's no
longer needed with advances in tier compilation, etc.
Thanks
- Ioi
On 2/20/20 10:33 AM, Magnus Ihse Bursie wrote:
20 feb. 2020 kl. 16:13 skrev Bob Vandette <bob.vande...@oracle.com>:
Keep in mind that any change here will have an impact on the jlink option that
allows for the
selection of JVM.
Jlink Plugin Name: vm
Option: --vm=<client | server | minimal | all>
Description: Select the HotSpot VM in the output image. Default is all
Good point.
I think if we remove building of multiple JVMs in the same pass, we need to
instead add an option to “import” additional JVMs. That way, the user can build
the JVM in a separate configuration, so we can simplify the logic to mean one
configuration == one JVM variant, and then it would still be possible to create
a resulting jimage that consists of multiple JVM variants.
/Magnus
Bob.
On Feb 20, 2020, at 10:04 AM, Magnus Ihse Bursie
<magnus.ihse.bur...@oracle.com> wrote:
On 2020-02-20 12:52, Baesken, Matthias wrote:
run a separate task with "configure --with-jvm-variants=minimal &&
make hotspot".
Hello, this would , as far as I know, not produce the same result jdk
image with both minimal+server libjvm in the image .
So the proposed change sounds a bit like a workaround, but not a real
replacement to what we have currently .
Well, almost. The resulting minimal/libjvm.so would reside in a different
directory, and would have to be copied into place. And the jvm.cfg file needs
to be correspondingly updated. All of this is trivial for you to do in your
wrapper CI scripts. Just as what Adrian does with zero. The simplicity of that
solution compared to the logistical nightmare in the make files does not make a
compelling case for keeping the multi-JVM support.
However if you do that, you *should* get the same result. If not, then it's a
bug somewhere (and that would really explain why this business of having
multiple JVMs is hairy!). Give it a try! You can use the compare.sh script to
verify that the resulting images are equal.
The one thing you need to take care of is making sure that the set of JVM
features that code outside Hotspot cares about is matching. This is one of the
thing the current system is trying hard to do (and failing, mostly, in all edge
cases). E.g., you need to either enable CDS on both the server and the minimal
build, or disable it on both.
/Magnus
Best Regards, Matthias
On 2020-02-19 16:59, Baesken, Matthias wrote:
Hi Magnus, yes we do. We build (on Linux only currently) "--with-jvm-
variants=minimal,server" in our central builds to test that minimal is still
working and that is was not destroyed by recent changes .
Best Regards, Matthias
Is this just to test that minimal is working? If so, you could just as
well run a separate task with "configure --with-jvm-variants=minimal &&
make hotspot". Unless you are actually shipping this configuration, that
does not seem like a solid reason for keeping this functionality in the
build.
/Magnus
