RFR (XS): 8078399: Deprecate -Xoss, -Xsqnopause, -Xoptimize and -Xboundthreads options in JDK 9
dmitry.dmitriev at oracle.com
Tue Jun 23 10:35:43 UTC 2015
Please review this small fix which deprecate -Xoss, -Xsqnopause,
-Xoptimize and -Xboundthreads options in JDK 9. Also, I need a sponsor
for this fix, who can push it.
Currently HotSpot silently ignore these 4 options. Here are description
of these options:
"-Xoss", "-Xsqnopause", "-Xoptimize" - EVM option leaved for
compatibility. From Java 2 SDK for Solaris Developer's Guide: "Prior to
version 1.3.0, the production releases of the Java 2 SDK for the Solaris
Operating Environment shipped with a virtual-machine implementation
known as the Exact VM (EVM). Beginning with version 1.3.0, the Exact VM
is replaced by the Java HotSpot VM.". So, from Java 1.4 EVM is not used
as VM for JDK on Solaris and these very old flags just silently ignored
"-Xboundthreads" - was used to bind user level threads to kernel threads
on Solaris in case when new thread library is not available. But old T1
libthread has been removed from Solaris in release 10. JDK9 requires
Solaris 10u9 or higher. So, this flag become useless.
All these options are deprecated, i.e. following warning is printed when
option is specified: "Java HotSpot(TM) 64-Bit Server VM warning: Option
-Xoss was deprecated in version 9.0 and will likely be removed in a
future release.". In next major release all these options can be removed.
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