Command reference

usage: ntprof <command> [options] [files]

Command	What it does
`record`	profile the running kernel or SPDK (needs root)
`report FILE...`	report recordings: the host's, and the target's
`compare BASE LOAD`	each stage's latency amplification (LAD) between two runs; a run is `host.ntp` or `host.ntp,target.ntp`
`probe`	check which hooks this kernel offers, and load them without attaching
`dump FILE...`	print the records of recordings as CSV
`version`	print the version

Record options

Option	Meaning
`-r, --role ROLE`	`host` (default), `target`, or `both`
`-t, --transport T`	`tcp` (default) or `rdma`
`-d, --duration SEC`	stop after SEC seconds (default: Ctrl-C)
`-i, --interval SEC`	one line per group every SEC seconds (default 1)
`--offline`	no interval lines, only the final report
`-s, --sample N`	record one command in N (default 1000); the host and the target must use the same N
`-o, --output FILE`	save the records to FILE
`--session DEV`	the namespace to profile, `nvmeXnY` (default: all)
`--io-type T`	`read`, `write`, or `both` (default)
`--size LIST`	only these I/O sizes, for example `4K,128K`
`--spdk-host PATH`	the host is SPDK: the binary with ntprof's probes (with a shared build, its libraries, comma-separated)
`--spdk-target PATH`	the target is SPDK, for example `build/bin/nvmf_tgt`
`--exact-queues`	count queue lengths per command (costs map operations on every I/O; default: the mean number in each stage, by Little's law)
`--btf DIR`	BTF from `tools/gen-btf.sh`, for kernels or modules without BTF
`--kprobes`	use kprobes even where fentry/fexit work
`--fentry`	use fentry/fexit even when a busy CPU would make attaching them wait

For record, report and compare:

Option	Meaning
`--detail`	every component, not only the stages
`--all-groups`	also groups with under 1 % of the records
`--aggregation A`	`avg` (mean, p50, p99, p99.9), `min`, `max`, or `dist` (all quantiles)
`-j, --json FILE`	write the final report as JSON

Option	Meaning
`-c, --config FILE`	a task file in ini format (`examples/ntprof.ini` in the repository lists every key); options on the command line override it
`-v, --verbose`	more messages (twice: libbpf's debug output)
`-h, --help`	the usage text; `-V, --version`: the version

NTPROF_SKIP=prog,prog leaves the named programs out, to measure what each hook costs.