Effect of setting -XX:+PerfDisableSharedMem JVM flag to false

Question

I was referred to this GC pause issue; it suggests setting -XX:+PerfDisableSharedMem JVM flag to false. My question is what happens when we set this flag to false,

Answer 1

Then /tmp/hsperfdata* won't be written. Which, according to hotspot-runtime-dev discussions, will prevent some performance monitoring command line tools from discovering running VMs automagically. They can still attach to the running process if the PID is specified explicitly.