Man pages matching name probe::ioscheduler.elv_add_request in section 3stap:

probe::ioscheduler.elv_add_request.3stap.en	debian 10 / systemtap-doc
probe::ioscheduler.elv_add_request.3stap.en	debian 11 / systemtap-doc
probe::ioscheduler.elv_add_request.3stap.en	debian 12 / systemtap-doc