blob: 3661a143d88d703a5c7a07122e824658e597d647 [file] [log] [blame]
# @lint-avoid-python-3-compatibility-imports
# ustat Activity stats from high-level languages, including exceptions,
# method calls, class loads, garbage collections, and more.
# For Linux, uses BCC, eBPF.
# USAGE: ustat [-l {java,node,perl,php,python,ruby,tcl}] [-C]
# [-S {cload,excp,gc,method,objnew,thread}] [-r MAXROWS] [-d]
# [interval [count]]
# This uses in-kernel eBPF maps to store per process summaries for efficiency.
# Newly-created processes might only be traced at the next interval, if the
# relevant USDT probe requires enabling through a semaphore.
# Copyright 2016 Sasha Goldshtein
# Licensed under the Apache License, Version 2.0 (the "License")
# 26-Oct-2016 Sasha Goldshtein Created this.
from __future__ import print_function
import argparse
from bcc import BPF, USDT
import os
from subprocess import call
from time import sleep, strftime
class Category(object):
GC = "GC"
class Probe(object):
def __init__(self, language, procnames, events):
Initialize a new probe object with a specific language, set of process
names to monitor for that language, and a dictionary of events and
categories. The dictionary is a mapping of USDT probe names (such as
'gc__start') to event categories supported by this tool -- from the
Category class.
self.language = language
self.procnames = procnames = events
def _find_targets(self):
"""Find pids where the comm is one of the specified list"""
self.targets = {}
all_pids = [int(pid) for pid in os.listdir('/proc') if pid.isdigit()]
for pid in all_pids:
comm = open('/proc/%d/comm' % pid).read().strip()
if comm in self.procnames:
cmdline = open('/proc/%d/cmdline' % pid).read()
self.targets[pid] = cmdline.replace('\0', ' ')
except IOError:
continue # process may already have terminated
def _enable_probes(self):
self.usdts = []
for pid in self.targets:
usdt = USDT(pid=pid)
for event in
usdt.enable_probe(event, "%s_%s" % (self.language, event))
except Exception:
# This process might not have a recent version of the USDT
# probes enabled, or might have been compiled without USDT
# probes at all. The process could even have been shut down
# and the pid been recycled. We have to gracefully handle
# the possibility that we can't attach probes to it at all.
def _generate_tables(self):
text = """
BPF_HASH(%s_%s_counts, u32, u64); // pid to event count
return str.join('', [text % (self.language, event)
for event in])
def _generate_functions(self):
text = """
int %s_%s(void *ctx) {
u64 *valp, zero = 0;
u32 tgid = bpf_get_current_pid_tgid() >> 32;
valp = %s_%s_counts.lookup_or_init(&tgid, &zero);
return 0;
lang = self.language
return str.join('', [text % (lang, event, lang, event)
for event in])
def get_program(self):
return self._generate_tables() + self._generate_functions()
def get_usdts(self):
return self.usdts
def get_counts(self, bpf):
"""Return a map of event counts per process"""
event_dict = dict([(category, 0) for category in])
result = dict([(pid, event_dict.copy()) for pid in self.targets])
for event, category in
counts = bpf["%s_%s_counts" % (self.language, event)]
for pid, count in counts.items():
result[pid.value][category] = count.value
return result
def cleanup(self):
self.usdts = None
class Tool(object):
def _parse_args(self):
examples = """examples:
./ustat # stats for all languages, 1 second refresh
./ustat -C # don't clear the screen
./ustat -l java # Java processes only
./ustat 5 # 5 second summaries
./ustat 5 10 # 5 second summaries, 10 times only
parser = argparse.ArgumentParser(
description="Activity stats from high-level languages.",
parser.add_argument("-l", "--language",
choices=["java", "node", "perl", "php", "python", "ruby", "tcl"],
help="language to trace (default: all languages)")
parser.add_argument("-C", "--noclear", action="store_true",
help="don't clear the screen")
parser.add_argument("-S", "--sort",
choices=[cat.lower() for cat in dir(Category) if cat.isupper()],
help="sort by this field (descending order)")
parser.add_argument("-r", "--maxrows", default=20, type=int,
help="maximum rows to print, default 20")
parser.add_argument("-d", "--debug", action="store_true",
help="Print the resulting BPF program (for debugging purposes)")
parser.add_argument("interval", nargs="?", default=1, type=int,
help="output interval, in seconds")
parser.add_argument("count", nargs="?", default=99999999, type=int,
help="number of outputs")
parser.add_argument("--ebpf", action="store_true",
self.args = parser.parse_args()
def _create_probes(self):
probes_by_lang = {
"java": Probe("java", ["java"], {
"gc__begin": Category.GC,
"mem__pool__gc__begin": Category.GC,
"thread__start": Category.THREAD,
"class__loaded": Category.CLOAD,
"object__alloc": Category.OBJNEW,
"method__entry": Category.METHOD,
"ExceptionOccurred__entry": Category.EXCP
"node": Probe("node", ["node"], {
"gc__start": Category.GC
"perl": Probe("perl", ["perl"], {
"sub__entry": Category.METHOD
"php": Probe("php", ["php"], {
"function__entry": Category.METHOD,
"compile__file__entry": Category.CLOAD,
"exception__thrown": Category.EXCP
"python": Probe("python", ["python"], {
"function__entry": Category.METHOD,
"gc__start": Category.GC
"ruby": Probe("ruby", ["ruby", "irb"], {
"method__entry": Category.METHOD,
"cmethod__entry": Category.METHOD,
"gc__mark__begin": Category.GC,
"gc__sweep__begin": Category.GC,
"object__create": Category.OBJNEW,
"hash__create": Category.OBJNEW,
"string__create": Category.OBJNEW,
"array__create": Category.OBJNEW,
"require__entry": Category.CLOAD,
"load__entry": Category.CLOAD,
"raise": Category.EXCP
"tcl": Probe("tcl", ["tclsh", "wish"], {
"proc__entry": Category.METHOD,
"obj__create": Category.OBJNEW
if self.args.language:
self.probes = [probes_by_lang[self.args.language]]
self.probes = probes_by_lang.values()
def _attach_probes(self):
program = str.join('\n', [p.get_program() for p in self.probes])
if self.args.debug or self.args.ebpf:
if self.args.ebpf:
for probe in self.probes:
print("Attached to %s processes:" % probe.language,
str.join(', ', map(str, probe.targets)))
self.bpf = BPF(text=program)
usdts = [usdt for probe in self.probes for usdt in probe.get_usdts()]
# Filter out duplicates when we have multiple processes with the same
# uprobe. We are attaching to these probes manually instead of using
# the USDT support from the bcc module, because the USDT class attaches
# to each uprobe with a specific pid. When there is more than one
# process from some language, we end up attaching more than once to the
# same uprobe (albeit with different pids), which is not allowed.
# Instead, we use a global attach (with pid=-1).
uprobes = set([(path, func, addr) for usdt in usdts
for (path, func, addr, _)
in usdt.enumerate_active_probes()])
for (path, func, addr) in uprobes:
self.bpf.attach_uprobe(name=path, fn_name=func, addr=addr, pid=-1)
def _detach_probes(self):
for probe in self.probes:
probe.cleanup() # Cleans up USDT contexts
self.bpf.cleanup() # Cleans up all attached probes
self.bpf = None
def _loop_iter(self):
except KeyboardInterrupt:
self.exiting = True
if not self.args.noclear:
with open("/proc/loadavg") as stats:
print("%-8s loadavg: %s" % (strftime("%H:%M:%S"),
print("%-6s %-20s %-10s %-6s %-10s %-8s %-6s %-6s" % (
"PID", "CMDLINE", "METHOD/s", "GC/s", "OBJNEW/s",
"CLOAD/s", "EXC/s", "THR/s"))
line = 0
counts = {}
targets = {}
for probe in self.probes:
if self.args.sort:
sort_field = self.args.sort.upper()
counts = sorted(counts.items(),
key=lambda kv: -kv[1].get(sort_field, 0))
counts = sorted(counts.items(), key=lambda kv: kv[0])
for pid, stats in counts:
print("%-6d %-20s %-10d %-6d %-10d %-8d %-6d %-6d" % (
pid, targets[pid][:20],
stats.get(Category.METHOD, 0) / self.args.interval,
stats.get(Category.GC, 0) / self.args.interval,
stats.get(Category.OBJNEW, 0) / self.args.interval,
stats.get(Category.CLOAD, 0) / self.args.interval,
stats.get(Category.EXCP, 0) / self.args.interval,
stats.get(Category.THREAD, 0) / self.args.interval
line += 1
if line >= self.args.maxrows:
def run(self):
print('Tracing... Output every %d secs. Hit Ctrl-C to end' %
countdown = self.args.count
self.exiting = False
while True:
countdown -= 1
if self.exiting or countdown == 0:
if __name__ == "__main__":
except KeyboardInterrupt: