scripts/python/flamegraph.py

0001 # flamegraph.py - create flame graphs from perf samples
0002 # SPDX-License-Identifier: GPL-2.0
0003 #
0004 # Usage:
0005 #
0006 #     perf record -a -g -F 99 sleep 60
0007 #     perf script report flamegraph
0008 #
0009 # Combined:
0010 #
0011 #     perf script flamegraph -a -F 99 sleep 60
0012 #
0013 # Written by Andreas Gerstmayr <agerstmayr@redhat.com>
0014 # Flame Graphs invented by Brendan Gregg <bgregg@netflix.com>
0015 # Works in tandem with d3-flame-graph by Martin Spier <mspier@netflix.com>
0016 #
0017 # pylint: disable=missing-module-docstring
0018 # pylint: disable=missing-class-docstring
0019 # pylint: disable=missing-function-docstring
0020
0021 from __future__ import print_function
0022 import sys
0023 import os
0024 import io
0025 import argparse
0026 import json
0027 import subprocess
0028
0029 # pylint: disable=too-few-public-methods
0030 class Node:
0031     def __init__(self, name, libtype):
0032         self.name = name
0033         # "root" | "kernel" | ""
0034         # "" indicates user space
0035         self.libtype = libtype
0036         self.value = 0
0037         self.children = []
0038
0039     def to_json(self):
0040         return {
0041             "n": self.name,
0042             "l": self.libtype,
0043             "v": self.value,
0044             "c": self.children
0045         }
0046
0047
0048 class FlameGraphCLI:
0049     def __init__(self, args):
0050         self.args = args
0051         self.stack = Node("all", "root")
0052
0053         if self.args.format == "html" and \
0054                 not os.path.isfile(self.args.template):
0055             print("Flame Graph template {} does not exist. Please install "
0056                   "the js-d3-flame-graph (RPM) or libjs-d3-flame-graph (deb) "
0057                   "package, specify an existing flame graph template "
0058                   "(--template PATH) or another output format "
0059                   "(--format FORMAT).".format(self.args.template),
0060                   file=sys.stderr)
0061             sys.exit(1)
0062
0063     @staticmethod
0064     def get_libtype_from_dso(dso):
0065         """
0066         when kernel-debuginfo is installed,
0067         dso points to /usr/lib/debug/lib/modules/*/vmlinux
0068         """
0069         if dso and (dso == "[kernel.kallsyms]" or dso.endswith("/vmlinux")):
0070             return "kernel"
0071
0072         return ""
0073
0074     @staticmethod
0075     def find_or_create_node(node, name, libtype):
0076         for child in node.children:
0077             if child.name == name:
0078                 return child
0079
0080         child = Node(name, libtype)
0081         node.children.append(child)
0082         return child
0083
0084     def process_event(self, event):
0085         pid = event.get("sample", {}).get("pid", 0)
0086         # event["dso"] sometimes contains /usr/lib/debug/lib/modules/*/vmlinux
0087         # for user-space processes; let's use pid for kernel or user-space distinction
0088         if pid == 0:
0089             comm = event["comm"]
0090             libtype = "kernel"
0091         else:
0092             comm = "{} ({})".format(event["comm"], pid)
0093             libtype = ""
0094         node = self.find_or_create_node(self.stack, comm, libtype)
0095
0096         if "callchain" in event:
0097             for entry in reversed(event["callchain"]):
0098                 name = entry.get("sym", {}).get("name", "[unknown]")
0099                 libtype = self.get_libtype_from_dso(entry.get("dso"))
0100                 node = self.find_or_create_node(node, name, libtype)
0101         else:
0102             name = event.get("symbol", "[unknown]")
0103             libtype = self.get_libtype_from_dso(event.get("dso"))
0104             node = self.find_or_create_node(node, name, libtype)
0105         node.value += 1
0106
0107     def get_report_header(self):
0108         if self.args.input == "-":
0109             # when this script is invoked with "perf script flamegraph",
0110             # no perf.data is created and we cannot read the header of it
0111             return ""
0112
0113         try:
0114             output = subprocess.check_output(["perf", "report", "--header-only"])
0115             return output.decode("utf-8")
0116         except Exception as err:  # pylint: disable=broad-except
0117             print("Error reading report header: {}".format(err), file=sys.stderr)
0118             return ""
0119
0120     def trace_end(self):
0121         stacks_json = json.dumps(self.stack, default=lambda x: x.to_json())
0122
0123         if self.args.format == "html":
0124             report_header = self.get_report_header()
0125             options = {
0126                 "colorscheme": self.args.colorscheme,
0127                 "context": report_header
0128             }
0129             options_json = json.dumps(options)
0130
0131             try:
0132                 with io.open(self.args.template, encoding="utf-8") as template:
0133                     output_str = (
0134                         template.read()
0135                         .replace("/** @options_json **/", options_json)
0136                         .replace("/** @flamegraph_json **/", stacks_json)
0137                     )
0138             except IOError as err:
0139                 print("Error reading template file: {}".format(err), file=sys.stderr)
0140                 sys.exit(1)
0141             output_fn = self.args.output or "flamegraph.html"
0142         else:
0143             output_str = stacks_json
0144             output_fn = self.args.output or "stacks.json"
0145
0146         if output_fn == "-":
0147             with io.open(sys.stdout.fileno(), "w", encoding="utf-8", closefd=False) as out:
0148                 out.write(output_str)
0149         else:
0150             print("dumping data to {}".format(output_fn))
0151             try:
0152                 with io.open(output_fn, "w", encoding="utf-8") as out:
0153                     out.write(output_str)
0154             except IOError as err:
0155                 print("Error writing output file: {}".format(err), file=sys.stderr)
0156                 sys.exit(1)
0157
0158
0159 if __name__ == "__main__":
0160     parser = argparse.ArgumentParser(description="Create flame graphs.")
0161     parser.add_argument("-f", "--format",
0162                         default="html", choices=["json", "html"],
0163                         help="output file format")
0164     parser.add_argument("-o", "--output",
0165                         help="output file name")
0166     parser.add_argument("--template",
0167                         default="/usr/share/d3-flame-graph/d3-flamegraph-base.html",
0168                         help="path to flame graph HTML template")
0169     parser.add_argument("--colorscheme",
0170                         default="blue-green",
0171                         help="flame graph color scheme",
0172                         choices=["blue-green", "orange"])
0173     parser.add_argument("-i", "--input",
0174                         help=argparse.SUPPRESS)
0175
0176     cli_args = parser.parse_args()
0177     cli = FlameGraphCLI(cli_args)
0178
0179     process_event = cli.process_event
0180     trace_end = cli.trace_end