Hi Volker,
v3 looks much cleaner - thanks.
But AFAICS the change to jvmtiEnv.cpp is also not needed.
ClassLoaderExt::append_boot_classpath exists regardless of INCLUDE_CDS
but operates differently (just calling
ClassLoader::add_to_boot_append_entries).
Thanks,
David
On 19/06/2018 2:04 AM, Volker Simonis wrote:
On Mon, Jun 18, 2018 at 8:17 AM, David Holmes <david.hol...@oracle.com> wrote:
Hi Volker,
src/hotspot/share/runtime/globals.hpp
This change should not be needed! We do minimal VM builds without CDS and we
don't have to touch the UseSharedSpaces defaults (unless recent change have
broken this - in which case that needs to be addressed in its own right!)
Yes, you're right, CDS_ONLY/NOT_CDS isn't really required here,
because UseSharedSpaces is reseted later on at the end of
Arguments::parse(). I just thought it would be cleaner to disable it
statically, if the VM doesn't support it. But anyway I don't really
mind and I've reverted that change in globals.hpp.
src/hotspot/share/classfile/javaClasses.cpp
AFAICS you should be using INCLUDE_CDS in the ifdefs not
INCLUDE_CDS_JAVA_HEAP. But again I'm unclear (as was Thomas) why this should
be needed as we have not needed it before. As Thomas notes we have:
./hotspot/share/memory/metaspaceShared.hpp: static bool
is_archive_object(oop p) NOT_CDS_JAVA_HEAP_RETURN_(false);
./hotspot/share/classfile/stringTable.hpp: static oop
create_archived_string(oop s, Thread* THREAD)
NOT_CDS_JAVA_HEAP_RETURN_(NULL);
so these methods should be defined when CDS is not available.
Thomas and you are right. Must have been a mis-configuration on AIX
where I saw undefined symbols at link time. I've removed the ifdefs
from javaClasses.cpp now.
Finally, I've also wrapped all the FileMapInfo fields in vmStructs.cpp
into CDS_ONLY macros as suggested by Jiangli because the really only
make sense for a CDS-enabled VM.
Here's the new webrev:
http://cr.openjdk.java.net/~simonis/webrevs/2018/8204965.v3/
Please let me know if you think there's still something missing.
Regards,
Volker
??
Thanks,
David
-----
On 15/06/2018 12:26 AM, Volker Simonis wrote:
Hi,
can I please have a review for the following fix:
http://cr.openjdk.java.net/~simonis/webrevs/2018/8204965/
https://bugs.openjdk.java.net/browse/JDK-8204965
CDS does currently not work on AIX because of the way how we
reserve/commit memory on AIX. The problem is that we're using a
combination of shmat/mmap depending on the page size and the size of
the memory chunk to reserve. This makes it impossible to reliably
reserve the memory for the CDS archive and later on map the various
parts of the archive into these regions.
In order to fix this we would have to completely rework the memory
reserve/commit/uncommit logic on AIX which is currently out of our
scope because of resource limitations.
Unfortunately, I could not simply disable CDS in the configure step
because some of the shared code apparently relies on parts of the CDS
code which gets excluded from the build when CDS is disabled. So I
also fixed the offending parts in hotspot and cleaned up the configure
logic for CDS.
Thank you and best regards,
Volker
PS: I did run the job through the submit forest
(mach5-one-simonis-JDK-8204965-20180613-1946-26349) but the results
weren't really useful because they mention build failures on linux-x64
which I can't reproduce locally.
