To avoid an extra load of cx->thread->data.interruptFlags when checking for operation callback invocations both methodjit and tracejit embed a pointer rt->interruptCounter. But this implies that the callback invocation on unrelated thread will trigger an extra check for cx->thread->data.interruptFlags by the method jit and trace exit for tracejit. To avoid this we need to consider moving interruptFlags into the compartment. But this is not trivial, see bug 589193 for details of the previous attempts.

This doesn't seem to be a regression, crash, or sg:crit.