A reader’s session and query interface for pid/koid mappings. Recording in the
kernel stays active while at least one session is held across any client; dropping
the session ends this client’s interest. When all active sessions have been dropped,
the shared map is released and recording ceases.
Kernel-wide manager of pid/tid to koid mappings, shared by all recording clients
(system tracing and CPU profiling). Stored in kernel.trace_event_manager.