> 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.
I think we should keep the praxis of only having server as default. > > The change in GensrcJFR.gmk fixes a newly introduced race that appears when > building multiple jvm variants. Thanks for fixing this! > > Bug: https://bugs.openjdk.java.net/browse/JDK-8202384 > > Webrev: http://cr.openjdk.java.net/~erikj/8202384/webrev.01 Looks good to me. /Magnus > > /Erik >
