Mic92 Default invocation prints a bounded text summary to stdout — paste it back.
# What is process X doing? (one process, wall-clock, 5s)
macprof sample <pid|name> 5 -o -
# Where is CPU time going system-wide? (true on-CPU, needs Xcode CL tools)
macprof xctrace 5 -o -
macprof xctrace 5 --attach <pid|name> -o -
# What is everything blocked on? (wall-clock, all procs, needs sudo)
macprof spindump 5 -o - --keep-idle
# Files for the user to open interactively
macprof xctrace 10 -o cpu.speedscope.json # → drop on https://speedscope.app
macprof spindump 10 # → cwd: .folded + .speedscope.json
Pick sampler by question:
| question | command |
|---|---|
| process hung / spinning, why? | sample <name> |
| what's burning CPU right now? | xctrace |
| system slow, who's blocking whom? | spindump |
Flags: -o - stdout summary · -o x.json speedscope · -o x.folded flamegraph
· --keep-idle include blocked threads · --keep-raw keep raw report.
Pair with heap <pid> (object counts) and lsof -p <pid> (open files/dirs)
when memory, not CPU, is the symptom.