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 <agerstmayr@redhat.com>
  14 # Flame Graphs invented by Brendan Gregg <bgregg@netflix.com>
  15 # Works in tandem with d3-flame-graph by Martin Spier <mspier@netflix.com>
  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 argparse
  23 import hashlib
  24 import io
  25 import json
  26 import os
  27 import subprocess
  28 import sys
  29 import urllib.request
  30
  31 minimal_html = """<head>
  32   <link rel="stylesheet" type="text/css" href="https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/d3-flamegraph.css">
  33 </head>
  34 <body>
  35   <div id="chart"></div>
  36   <script type="text/javascript" src="https://d3js.org/d3.v7.js"></script>
  37   <script type="text/javascript" src="https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/d3-flamegraph.min.js"></script>
  38   <script type="text/javascript">
  39   const stacks = [/** @flamegraph_json **/];
  40   // Note, options is unused.
  41   const options = [/** @options_json **/];
  42
  43   var chart = flamegraph();
  44   d3.select("#chart")
  45         .datum(stacks[0])
  46         .call(chart);
  47   </script>
  48 </body>
  49 """
  50
  51 # pylint: disable=too-few-public-methods
  52 class Node:
  53     def __init__(self, name, libtype):
  54         self.name = name
  55         # "root" | "kernel" | ""
  56         # "" indicates user space
  57         self.libtype = libtype
  58         self.value = 0
  59         self.children = []
  60
  61     def to_json(self):
  62         return {
  63             "n": self.name,
  64             "l": self.libtype,
  65             "v": self.value,
  66             "c": self.children
  67         }
  68
  69
  70 class FlameGraphCLI:
  71     def __init__(self, args):
  72         self.args = args
  73         self.stack = Node("all", "root")
  74
  75     @staticmethod
  76     def get_libtype_from_dso(dso):
  77         """
  78         when kernel-debuginfo is installed,
  79         dso points to /usr/lib/debug/lib/modules/*/vmlinux
  80         """
  81         if dso and (dso == "[kernel.kallsyms]" or dso.endswith("/vmlinux")):
  82             return "kernel"
  83
  84         return ""
  85
  86     @staticmethod
  87     def find_or_create_node(node, name, libtype):
  88         for child in node.children:
  89             if child.name == name:
  90                 return child
  91
  92         child = Node(name, libtype)
  93         node.children.append(child)
  94         return child
  95
  96     def process_event(self, event):
  97         pid = event.get("sample", {}).get("pid", 0)
  98         # event["dso"] sometimes contains /usr/lib/debug/lib/modules/*/vmlinux
  99         # for user-space processes; let's use pid for kernel or user-space distinction
 100         if pid == 0:
 101             comm = event["comm"]
 102             libtype = "kernel"
 103         else:
 104             comm = "{} ({})".format(event["comm"], pid)
 105             libtype = ""
 106         node = self.find_or_create_node(self.stack, comm, libtype)
 107
 108         if "callchain" in event:
 109             for entry in reversed(event["callchain"]):
 110                 name = entry.get("sym", {}).get("name", "[unknown]")
 111                 libtype = self.get_libtype_from_dso(entry.get("dso"))
 112                 node = self.find_or_create_node(node, name, libtype)
 113         else:
 114             name = event.get("symbol", "[unknown]")
 115             libtype = self.get_libtype_from_dso(event.get("dso"))
 116             node = self.find_or_create_node(node, name, libtype)
 117         node.value += 1
 118
 119     def get_report_header(self):
 120         if self.args.input == "-":
 121             # when this script is invoked with "perf script flamegraph",
 122             # no perf.data is created and we cannot read the header of it
 123             return ""
 124
 125         try:
 126             output = subprocess.check_output(["perf", "report", "--header-only"])
 127             return output.decode("utf-8")
 128         except Exception as err:  # pylint: disable=broad-except
 129             print("Error reading report header: {}".format(err), file=sys.stderr)
 130             return ""
 131
 132     def trace_end(self):
 133         stacks_json = json.dumps(self.stack, default=lambda x: x.to_json())
 134
 135         if self.args.format == "html":
 136             report_header = self.get_report_header()
 137             options = {
 138                 "colorscheme": self.args.colorscheme,
 139                 "context": report_header
 140             }
 141             options_json = json.dumps(options)
 142
 143             template_md5sum = None
 144             if self.args.format == "html":
 145                 if os.path.isfile(self.args.template):
 146                     template = f"file://{self.args.template}"
 147                 else:
 148                     if not self.args.allow_download:
 149                         print(f"""Warning: Flame Graph template '{self.args.template}'
 150 does not exist. To avoid this please install a package such as the
 151 js-d3-flame-graph or libjs-d3-flame-graph, specify an existing flame
 152 graph template (--template PATH) or use another output format (--format
 153 FORMAT).""",
 154                               file=sys.stderr)
 155                         if self.args.input == "-":
 156                             print("""Not attempting to download Flame Graph template as script command line
 157 input is disabled due to using live mode. If you want to download the
 158 template retry without live mode. For example, use 'perf record -a -g
 159 -F 99 sleep 60' and 'perf script report flamegraph'. Alternatively,
 160 download the template from:
 161 https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/templates/d3-flamegraph-base.html
 162 and place it at:
 163 /usr/share/d3-flame-graph/d3-flamegraph-base.html""",
 164                                   file=sys.stderr)
 165                             quit()
 166                         s = None
 167                         while s != "y" and s != "n":
 168                             s = input("Do you wish to download a template from cdn.jsdelivr.net? (this warning can be suppressed with --allow-download) [yn] ").lower()
 169                         if s == "n":
 170                             quit()
 171                     template = "https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/templates/d3-flamegraph-base.html"
 172                     template_md5sum = "143e0d06ba69b8370b9848dcd6ae3f36"
 173
 174             try:
 175                 with urllib.request.urlopen(template) as template:
 176                     output_str = "".join([
 177                         l.decode("utf-8") for l in template.readlines()
 178                     ])
 179             except Exception as err:
 180                 print(f"Error reading template {template}: {err}\n"
 181                       "a minimal flame graph will be generated", file=sys.stderr)
 182                 output_str = minimal_html
 183                 template_md5sum = None
 184
 185             if template_md5sum:
 186                 download_md5sum = hashlib.md5(output_str.encode("utf-8")).hexdigest()
 187                 if download_md5sum != template_md5sum:
 188                     s = None
 189                     while s != "y" and s != "n":
 190                         s = input(f"""Unexpected template md5sum.
 191 {download_md5sum} != {template_md5sum}, for:
 192 {output_str}
 193 continue?[yn] """).lower()
 194                     if s == "n":
 195                         quit()
 196
 197             output_str = output_str.replace("/** @options_json **/", options_json)
 198             output_str = output_str.replace("/** @flamegraph_json **/", stacks_json)
 199
 200             output_fn = self.args.output or "flamegraph.html"
 201         else:
 202             output_str = stacks_json
 203             output_fn = self.args.output or "stacks.json"
 204
 205         if output_fn == "-":
 206             with io.open(sys.stdout.fileno(), "w", encoding="utf-8", closefd=False) as out:
 207                 out.write(output_str)
 208         else:
 209             print("dumping data to {}".format(output_fn))
 210             try:
 211                 with io.open(output_fn, "w", encoding="utf-8") as out:
 212                     out.write(output_str)
 213             except IOError as err:
 214                 print("Error writing output file: {}".format(err), file=sys.stderr)
 215                 sys.exit(1)
 216
 217
 218 if __name__ == "__main__":
 219     parser = argparse.ArgumentParser(description="Create flame graphs.")
 220     parser.add_argument("-f", "--format",
 221                         default="html", choices=["json", "html"],
 222                         help="output file format")
 223     parser.add_argument("-o", "--output",
 224                         help="output file name")
 225     parser.add_argument("--template",
 226                         default="/usr/share/d3-flame-graph/d3-flamegraph-base.html",
 227                         help="path to flame graph HTML template")
 228     parser.add_argument("--colorscheme",
 229                         default="blue-green",
 230                         help="flame graph color scheme",
 231                         choices=["blue-green", "orange"])
 232     parser.add_argument("-i", "--input",
 233                         help=argparse.SUPPRESS)
 234     parser.add_argument("--allow-download",
 235                         default=False,
 236                         action="store_true",
 237                         help="allow unprompted downloading of HTML template")
 238
 239     cli_args = parser.parse_args()
 240     cli = FlameGraphCLI(cli_args)
 241
 242     process_event = cli.process_event
 243     trace_end = cli.trace_end