# flamegraph.py - create flame graphs from perf samples
# SPDX-License-Identifier: GPL-2.0
#
# Usage:
#
# perf record -a -g -F 99 sleep 60
# perf script report flamegraph
#
# Combined:
#
# perf script flamegraph -a -F 99 sleep 60
#
# Written by Andreas Gerstmayr <agerstmayr@redhat.com>
# Flame Graphs invented by Brendan Gregg <bgregg@netflix.com>
# Works in tandem with d3-flame-graph by Martin Spier <mspier@netflix.com>
#
# pylint: disable=missing-module-docstring
# pylint: disable=missing-class-docstring
# pylint: disable=missing-function-docstring
from __future__ import print_function
import argparse
import hashlib
import io
import json
import os
import subprocess
import sys
import urllib.request
minimal_html = """<head>
<link rel="stylesheet" type="text/css" href="https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/d3-flamegraph.css">
</head>
<body>
<div id="chart"></div>
<script type="text/javascript" src="https://d3js.org/d3.v7.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/d3-flamegraph.min.js"></script>
<script type="text/javascript">
const stacks = [/** @flamegraph_json **/];
// Note, options is unused.
const options = [/** @options_json **/];
var chart = flamegraph();
d3.select("#chart")
.datum(stacks[0])
.call(chart);
</script>
</body>
"""
# pylint: disable=too-few-public-methods
class Node:
def __init__(self, name, libtype):
self.name = name
# "root" | "kernel" | ""
# "" indicates user space
self.libtype = libtype
self.value = 0
self.children = []
def to_json(self):
return {
"n": self.name,
"l": self.libtype,
"v": self.value,
"c": self.children
}
class FlameGraphCLI:
def __init__(self, args):
self.args = args
self.stack = Node("all", "root")
@staticmethod
def get_libtype_from_dso(dso):
"""
when kernel-debuginfo is installed,
dso points to /usr/lib/debug/lib/modules/*/vmlinux
"""
if dso and (dso == "[kernel.kallsyms]" or dso.endswith("/vmlinux")):
return "kernel"
return ""
@staticmethod
def find_or_create_node(node, name, libtype):
for child in node.children:
if child.name == name:
return child
child = Node(name, libtype)
node.children.append(child)
return child
def process_event(self, event):
pid = event.get("sample", {}).get("pid", 0)
# event["dso"] sometimes contains /usr/lib/debug/lib/modules/*/vmlinux
# for user-space processes; let's use pid for kernel or user-space distinction
if pid == 0:
comm = event["comm"]
libtype = "kernel"
else:
comm = "{} ({})".format(event["comm"], pid)
libtype = ""
node = self.find_or_create_node(self.stack, comm, libtype)
if "callchain" in event:
for entry in reversed(event["callchain"]):
name = entry.get("sym", {}).get("name", "[unknown]")
libtype = self.get_libtype_from_dso(entry.get("dso"))
node = self.find_or_create_node(node, name, libtype)
else:
name = event.get("symbol", "[unknown]")
libtype = self.get_libtype_from_dso(event.get("dso"))
node = self.find_or_create_node(node, name, libtype)
node.value += 1
def get_report_header(self):
if self.args.input == "-":
# when this script is invoked with "perf script flamegraph",
# no perf.data is created and we cannot read the header of it
return ""
try:
output = subprocess.check_output(["perf", "report", "--header-only"])
return output.decode("utf-8")
except Exception as err: # pylint: disable=broad-except
print("Error reading report header: {}".format(err), file=sys.stderr)
return ""
def trace_end(self):
stacks_json = json.dumps(self.stack, default=lambda x: x.to_json())
if self.args.format == "html":
report_header = self.get_report_header()
options = {
"colorscheme": self.args.colorscheme,
"context": report_header
}
options_json = json.dumps(options)
template_md5sum = None
if self.args.format == "html":
if os.path.isfile(self.args.template):
template = f"file://{self.args.template}"
else:
if not self.args.allow_download:
print(f"""Warning: Flame Graph template '{self.args.template}'
does not exist. To avoid this please install a package such as the
js-d3-flame-graph or libjs-d3-flame-graph, specify an existing flame
graph template (--template PATH) or use another output format (--format
FORMAT).""",
file=sys.stderr)
if self.args.input == "-":
print("""Not attempting to download Flame Graph template as script command line
input is disabled due to using live mode. If you want to download the
template retry without live mode. For example, use 'perf record -a -g
-F 99 sleep 60' and 'perf script report flamegraph'. Alternatively,
download the template from:
https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/templates/d3-flamegraph-base.html
and place it at:
/usr/share/d3-flame-graph/d3-flamegraph-base.html""",
file=sys.stderr)
quit()
s = None
while s != "y" and s != "n":
s = input("Do you wish to download a template from cdn.jsdelivr.net? (this warning can be suppressed with --allow-download) [yn] ").lower()
if s == "n":
quit()
template = "https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/templates/d3-flamegraph-base.html"
template_md5sum = "143e0d06ba69b8370b9848dcd6ae3f36"
try:
with urllib.request.urlopen(template) as template:
output_str = "".join([
l.decode("utf-8") for l in template.readlines()
])
except Exception as err:
print(f"Error reading template {template}: {err}\n"
"a minimal flame graph will be generated", file=sys.stderr)
output_str = minimal_html
template_md5sum = None
if template_md5sum:
download_md5sum = hashlib.md5(output_str.encode("utf-8")).hexdigest()
if download_md5sum != template_md5sum:
s = None
while s != "y" and s != "n":
s = input(f"""Unexpected template md5sum.
{download_md5sum} != {template_md5sum}, for:
{output_str}
continue?[yn] """).lower()
if s == "n":
quit()
output_str = output_str.replace("/** @options_json **/", options_json)
output_str = output_str.replace("/** @flamegraph_json **/", stacks_json)
output_fn = self.args.output or "flamegraph.html"
else:
output_str = stacks_json
output_fn = self.args.output or "stacks.json"
if output_fn == "-":
with io.open(sys.stdout.fileno(), "w", encoding="utf-8", closefd=False) as out:
out.write(output_str)
else:
print("dumping data to {}".format(output_fn))
try:
with io.open(output_fn, "w", encoding="utf-8") as out:
out.write(output_str)
except IOError as err:
print("Error writing output file: {}".format(err), file=sys.stderr)
sys.exit(1)
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Create flame graphs.")
parser.add_argument("-f", "--format",
default="html", choices=["json", "html"],
help="output file format")
parser.add_argument("-o", "--output",
help="output file name")
parser.add_argument("--template",
default="/usr/share/d3-flame-graph/d3-flamegraph-base.html",
help="path to flame graph HTML template")
parser.add_argument("--colorscheme",
default="blue-green",
help="flame graph color scheme",
choices=["blue-green", "orange"])
parser.add_argument("-i", "--input",
help=argparse.SUPPRESS)
parser.add_argument("--allow-download",
default=False,
action="store_true",
help="allow unprompted downloading of HTML template")
cli_args = parser.parse_args()
cli = FlameGraphCLI(cli_args)
process_event = cli.process_event
trace_end = cli.trace_end