| EU-STACKPROF(1) | General Commands Manual | EU-STACKPROF(1) |
NAME
eu-stackprof - collect a multi-process stack profile
SYNOPSIS
eu-stackprof [-v|-vv|...] [--gmon] [-o DEST] [OPTION]... [-- CMD...]
DESCRIPTION
eu-stackprof collects stack profile data from Linux perf_events, either systemwide across all processes or targeted to a particular process (existing PID via -p or newly launched from provided command line arguments) and any children forked from it. Appropriate privileges are needed to access the perf_events interface, either globally or for a particular targeted process; refer to perf_event_open(2) section "Arguments" for a summary of the privilege requirements.
When the --gmon option is used, results are saved as gmon.out files in the gprof(1) format. These are intended to be useful for statistics collection with profiledb.
When the --gmon option is not used, eu-stackprof will collect and print basic statistics about the profile data to standard error.
OPTIONS
- -e EVENT, --event=EVENT
- Configure perf_events sampling according to the provided libpfm event specification (e.g. perf::CPU-CLOCK:freq=1000).
- --event-list
- List available libpfm events and exit.
- -f, --force
- If the output directory for --gmon already contains files identified by the encountered build-ids, overwrite them with the newly collected data.
- -g, --gmon
- Output program counter histograms and callgraphs for each executable binary encountered during profiling in gprof(1)'s gmon.out format.
- -G METHOD, --hist-split=METHOD
- Specify the method used to divide the address space into histograms for --gmon output. METHOD should be one of:
- none
- Don't split: write one histogram covering the whole address range.
- even (default)
- Split address space into histograms of equal size to satisfy gprof(1)'s scale consistency check.
- flex
- Split address space into variable-sized histograms to minimize storage requirements; result will likely be rejected by the gprof(1) tool, which requires all histograms to have a consistent scale, but should still be suitable for profiledb.
- -?, --help
- Print a short list of options.
- -n MAXFRAMES, --maxframes=MAXFRAMES
- Upper bound on the number of frames to unwind for each stack sample. Defaults to 1 if --gmon is enabled, since additional frames beyond the first are not needed to produce the gprof histogram and callgraph arc data; defaults to 256 otherwise.
- -o DEST, --output=DEST
- Directory where to write results when --gmon output is enabled. Defaults to the current directory.
- -p PID, --pid=PID
- Restrict the profile to process PID and its future children.
- -v, --verbose
- Output additional information. May be given once or multiple times to increase the granularity, logging each new binary, each stack sample, or each frame.
- -V, --version
- Print program version.
OUTPUT FORMAT
When --gmon output is enabled, eu-stackprof produces the following files for each executable object observed among the profiled processes, identified by build-id:
- gmon.BUILDID.exe
-
Symlink to the executable object observed by the profiler.
- gmon.BUILDID.out
-
Contains a histogram of program counters and a table of callgraph arcs (observed from the top 2 frames of the stacktrace). Same format as produced by the gprof infrastructure and consumed by gprof(1).
- gmon.BUILDID.json
-
Metadata in JSON format, including the path to the executable object and libpfm event information.
EXAMPLES
Profile system-wide; write gmon.out files to current directory:
sudo eu-stackprof --gmon
Profile PID 1211 and children forked from it; log one line per
stack sample; write gmon.out files to results/, replacing any
already-existing files with the same build-ids:
sudo eu-stackprof -vv --gmon -o results/ -p 1211 --force
Likewise, launch vim and profile it:
sudo eu-stackprof --gmon -o results/ --force -- vim test.txt
Profile system-wide; log one line per stack frame:
sudo eu-stackprof -vvv
REPORTING BUGS
Report bugs to <elfutils-devel@sourceware.org> or https://sourceware.org/bugzilla/.
SEE ALSO
| 2026-Apr-10 | elfutils |