- profile --nmi | --rtc sets the profiling mode
- --rtc is default, uses BIOS RTC, cannot profile kernel the presetted
frequency values apply
- --nmi is only available in APIC mode as it uses the NMI watchdog, -f
allows any frequency in Hz
- both modes use compatible data structures
- when kernel profiles a process for the first time it saves an entry
describing the process [endpoint|name]
- every profile sample is only [endpoint|pc]
- profile utility creates a table of endpoint <-> name relations and
translates endpoints of samples into names and writing out the
results to comply with the processing tools
- "task" endpoints like KERNEL are negative thus we must cast it to
unsigned when hashing