RFR(M): 8204965: Fix '--disable-cds' and disable CDS on AIX by default

[Erik Joelsson]

Build changes look ok.

/Erik


On 2018-06-14 07:26, 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.