What the engine found it could use. Backends fill in what applies.
Fields
- single_issuer: bool
- io_uring: the setup flags the kernel accepted.
- defer_taskrun: bool
- coop_taskrun: bool
- ext_arg: bool
- io_uring: waits with a timeout in one call (Linux 5.11).
- kernel_ops: s64
- io_uring: how many operations the kernel's probe lists.