Currently native method pageSize() used to cause deliberate transactional aborts is not marked to be compiled and so that method is never called through the code path of SharedRuntime::generate_native_wrapper() as it's excluded from compilation (passing -XX:+PrintCompilation):

### Excluding generation of native wrapper: jdk.internal.misc.Unsafe::pageSize
made not compilable on levels 0 1 2 3 4 jdk.internal.misc.Unsafe::pageSize excluded by CompileCommand
 
It means that the abort due to calling a native method never takes place and programmed aborts in TestRTMAbortRatio never in fact occur.

I can't for sure say way that test is getting the correct number of aborts on x86. however I can confirm that even on x86 the aborts do not come from the native wrapper. I suspect the aborts on x86 are occurring a bit latter when the native function is called and a "Far Call" is executed in the native method by chance and not deliberately (in a controlled way).

Anyway, just marking the pageSize() native method as compilable makes it pass on Power (as expected) and causes no regression on Intel since the abort in SharedRuntime::generate_native_wrapper() takes effect.