This magic interface provide a special channel for cache to talk with an underliying PFC monitor with non-uniform requirement. For example, a cache capable of relocating cache blocks may need to count the number of relocations in a period of time. This info cannot be collected using the typical PFC interface. With this magic interface, the relocation method can directly call a monitor using a predefined magic id, to record such events. When none of such monitor is available/enabled/attached, there is barely any side-effect expcet for a fruitless seasrch of all attached monitors, which normally are with a tiny number.
This magic interface provide a special channel for cache to talk with an underliying PFC monitor with non-uniform requirement. For example, a cache capable of relocating cache blocks may need to count the number of relocations in a period of time. This info cannot be collected using the typical PFC interface. With this magic interface, the relocation method can directly call a monitor using a predefined magic id, to record such events. When none of such monitor is available/enabled/attached, there is barely any side-effect expcet for a fruitless seasrch of all attached monitors, which normally are with a tiny number.