Hi,
I'm trying to figure out the right way to patch an instruction that is concurrently being executed on another core, possibly even on a separate socket. The only place in the Intel manual where something like this is mentioned is Volume 3 (System Programming Guide) / Section 8.1.3, where the manual says the patching thread and the executing thread need to implement a mutex-like protocol. I'd like to know if the protocol mentioned in 8.1.3 is required on newer Intel chips or if newer Intel chips in practice have a stronger guarantee around code patching that will let me implement something cheaper. I don't really care about making the patching thread fast (since we'll patch instructions very rarely), but the we're not okay with slowing down the executing thread.
-- Sanjoy