tools/perf/scripts/python/flamegraph.py

   1 # flamegraph.py - create flame graphs from perf samples
   2 # SPDX-License-Identifier: GPL-2.0
   3 #
   4 # Usage:
   5 #
   6 #     perf record -a -g -F 99 sleep 60
   7 #     perf script report flamegraph
   8 #
   9 # Combined:
  10 #
  11 #     perf script flamegraph -a -F 99 sleep 60
  12 #
  13 # Written by Andreas Gerstmayr <[email protected]>
  14 # Flame Graphs invented by Brendan Gregg <[email protected]>
  15 # Works in tandem with d3-flame-graph by Martin Spier <[email protected]>
  16 #
  17 # pylint: disable=missing-module-docstring
  18 # pylint: disable=missing-class-docstring
  19 # pylint: disable=missing-function-docstring
  20
  21 from __future__ import print_function
  22 import sys
  23 import os
  24 import io
  25 import argparse
  26 import json
  27 import subprocess
  28
  29 # pylint: disable=too-few-public-methods
  30 class Node:
  31     def __init__(self, name, libtype):
  32         self.name = name
  33         # "root" | "kernel" | ""
  34         # "" indicates user space
  35         self.libtype = libtype
  36         self.value = 0
  37         self.children = []
  38
  39     def to_json(self):
  40         return {
  41             "n": self.name,
  42             "l": self.libtype,
  43             "v": self.value,
  44             "c": self.children
  45         }
  46
  47
  48 class FlameGraphCLI:
  49     def __init__(self, args):
  50         self.args = args
  51         self.stack = Node("all", "root")
  52
  53         if self.args.format == "html" and \
  54                 not os.path.isfile(self.args.template):
  55             print("Flame Graph template {} does not exist. Please install "
  56                   "the js-d3-flame-graph (RPM) or libjs-d3-flame-graph (deb) "
  57                   "package, specify an existing flame graph template "
  58                   "(--template PATH) or another output format "
  59                   "(--format FORMAT).".format(self.args.template),
  60                   file=sys.stderr)
  61             sys.exit(1)
  62
  63     @staticmethod
  64     def get_libtype_from_dso(dso):
  65         """
  66         when kernel-debuginfo is installed,
  67         dso points to /usr/lib/debug/lib/modules/*/vmlinux
  68         """
  69         if dso and (dso == "[kernel.kallsyms]" or dso.endswith("/vmlinux")):
  70             return "kernel"
  71
  72         return ""
  73
  74     @staticmethod
  75     def find_or_create_node(node, name, libtype):
  76         for child in node.children:
  77             if child.name == name:
  78                 return child
  79
  80         child = Node(name, libtype)
  81         node.children.append(child)
  82         return child
  83
  84     def process_event(self, event):
  85         pid = event.get("sample", {}).get("pid", 0)
  86         # event["dso"] sometimes contains /usr/lib/debug/lib/modules/*/vmlinux
  87         # for user-space processes; let's use pid for kernel or user-space distinction
  88         if pid == 0:
  89             comm = event["comm"]
  90             libtype = "kernel"
  91         else:
  92             comm = "{} ({})".format(event["comm"], pid)
  93             libtype = ""
  94         node = self.find_or_create_node(self.stack, comm, libtype)
  95
  96         if "callchain" in event:
  97             for entry in reversed(event["callchain"]):
  98                 name = entry.get("sym", {}).get("name", "[unknown]")
  99                 libtype = self.get_libtype_from_dso(entry.get("dso"))
 100                 node = self.find_or_create_node(node, name, libtype)
 101         else:
 102             name = event.get("symbol", "[unknown]")
 103             libtype = self.get_libtype_from_dso(event.get("dso"))
 104             node = self.find_or_create_node(node, name, libtype)
 105         node.value += 1
 106
 107     def get_report_header(self):
 108         if self.args.input == "-":
 109             # when this script is invoked with "perf script flamegraph",
 110             # no perf.data is created and we cannot read the header of it
 111             return ""
 112
 113         try:
 114             output = subprocess.check_output(["perf", "report", "--header-only"])
 115             return output.decode("utf-8")
 116         except Exception as err:  # pylint: disable=broad-except
 117             print("Error reading report header: {}".format(err), file=sys.stderr)
 118             return ""
 119
 120     def trace_end(self):
 121         stacks_json = json.dumps(self.stack, default=lambda x: x.to_json())
 122
 123         if self.args.format == "html":
 124             report_header = self.get_report_header()
 125             options = {
 126                 "colorscheme": self.args.colorscheme,
 127                 "context": report_header
 128             }
 129             options_json = json.dumps(options)
 130
 131             try:
 132                 with io.open(self.args.template, encoding="utf-8") as template:
 133                     output_str = (
 134                         template.read()
 135                         .replace("/** @options_json **/", options_json)
 136                         .replace("/** @flamegraph_json **/", stacks_json)
 137                     )
 138             except IOError as err:
 139                 print("Error reading template file: {}".format(err), file=sys.stderr)
 140                 sys.exit(1)
 141             output_fn = self.args.output or "flamegraph.html"
 142         else:
 143             output_str = stacks_json
 144             output_fn = self.args.output or "stacks.json"
 145
 146         if output_fn == "-":
 147             with io.open(sys.stdout.fileno(), "w", encoding="utf-8", closefd=False) as out:
 148                 out.write(output_str)
 149         else:
 150             print("dumping data to {}".format(output_fn))
 151             try:
 152                 with io.open(output_fn, "w", encoding="utf-8") as out:
 153                     out.write(output_str)
 154             except IOError as err:
 155                 print("Error writing output file: {}".format(err), file=sys.stderr)
 156                 sys.exit(1)
 157
 158
 159 if __name__ == "__main__":
 160     parser = argparse.ArgumentParser(description="Create flame graphs.")
 161     parser.add_argument("-f", "--format",
 162                         default="html", choices=["json", "html"],
 163                         help="output file format")
 164     parser.add_argument("-o", "--output",
 165                         help="output file name")
 166     parser.add_argument("--template",
 167                         default="/usr/share/d3-flame-graph/d3-flamegraph-base.html",
 168                         help="path to flame graph HTML template")
 169     parser.add_argument("--colorscheme",
 170                         default="blue-green",
 171                         help="flame graph color scheme",
 172                         choices=["blue-green", "orange"])
 173     parser.add_argument("-i", "--input",
 174                         help=argparse.SUPPRESS)
 175
 176     cli_args = parser.parse_args()
 177     cli = FlameGraphCLI(cli_args)
 178
 179     process_event = cli.process_event
 180     trace_end = cli.trace_end