/Magnus
> 1 juni 2018 kl. 23:53 skrev Erik Joelsson <erik.joels...@oracle.com>:
>
> We need to add compilation flags for disabling speculative execution to our
> native libraries and executables. In order to allow for users not affected by
> problems with speculative execution to run a JVM at full speed, we need to be
> able to ship two JVM libraries - one that is compiled with speculative
> execution enabled, and one that is compiled without. Note that this applies
> to the build time C++ flags, not the compiler in the JVM itself. Luckily
> adding these flags to the rest of the native libraries did not have a
> significant performance impact so there is no need for making it optional
> there.
>
> This patch defines flags for disabling speculative execution for GCC and
> Visual Studio and applies them to all binaries except libjvm when available
> in the compiler. It defines a new jvm feature no-speculative-cti, which is
> used to control whether to use the flags for libjvm. It also defines a new
> jvm variant "altserver" which is the same as server, but with this new
> feature added.
>
> For Oracle builds, we are changing the default for linux-x64 and windows-x64
> to build both server and altserver, giving the choice to the user which JVM
> they want to use. If others would prefer this default, we could make it
> default in configure as well.
>
> The change in GensrcJFR.gmk fixes a newly introduced race that appears when
> building multiple jvm variants.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8202384
>
> Webrev: http://cr.openjdk.java.net/~erikj/8202384/webrev.01
>
> /Erik
>
