v8/tools/memory/rss.py
Jakob Kummerow dce8a257fd [tools] Add tools/memory/rss.py to sample RSS usage
Similar to how `time COMMAND` measures time, `rss.py COMMAND` measures
memory consumption, by sampling RSS (Resident Set Size) for the child
process in /proc at a configurable interval (default: every 1ms).

No-Try: true
Change-Id: I381cdd6325fae67944ee96e44ba09dd948d432cd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3971360
Reviewed-by: Matthias Liedtke <mliedtke@chromium.org>
Auto-Submit: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Matthias Liedtke <mliedtke@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83858}
2022-10-21 16:38:40 +00:00

96 lines
2.6 KiB
Python
Executable File

#!/usr/bin/env python3
# Copyright 2022 the V8 project authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
import subprocess
import sys
import time
kDefaultSamplerateSecs = 0.001
def PrintHelp(returncode):
print(f"""Usage: {sys.argv[0]} [--interval I] [--freq F] [--] COMMAND
Runs COMMAND, and samples its RSS memory usage every I milliseconds (or F \
times per second).
Default sample interval is {kDefaultSamplerateSecs * 1000} ms.
'--' as argument forces all further arguments to be part of COMMAND.
""")
sys.exit(returncode)
def Main():
# Parse arguments.
args = []
samplerate_secs = kDefaultSamplerateSecs
idx = 1
while idx < len(sys.argv):
arg = sys.argv[idx]
if arg == "--":
args += sys.argv[(idx + 1):]
break
if arg in ("-h", "--help", "help"):
PrintHelp(0)
elif arg in ("--interval", "-I"):
if idx + 1 >= len(sys.argv):
PrintHelp(1)
samplerate_secs = int(sys.argv[idx + 1]) / 1000
idx += 1 # Skip the value.
elif arg in ("--freq", "-F"):
if idx + 1 >= len(sys.argv):
PrintHelp(1)
samplerate_secs = 1 / float(sys.argv[idx + 1])
idx += 1 # Skip the value.
else:
# No match for known parameter; assume it's part of the command to run.
args.append(arg)
idx += 1 # Go to next arg.
cmd = " ".join(args)
print(f"sample rate: {samplerate_secs}")
print(f"command: {cmd}")
# Run the child process and observe it.
process = subprocess.Popen(cmd, shell=True)
pid = process.pid
print(f"pid: {pid}")
statusfile = f"/proc/{pid}/status"
vmsum = 0
observed_max = 0
reported_max = 0
sample_count = 0
while process.poll() is None:
with open(statusfile, 'r') as f:
for line in f.read().splitlines():
if line.startswith("VmRSS"):
rss = int(line.split()[1])
vmsum += rss
if rss > observed_max:
observed_max = rss
elif line.startswith("VmHWM"):
peak = int(line.split()[1])
if peak > reported_max:
reported_max = peak
sample_count += 1
time.sleep(samplerate_secs)
# Report findings.
print("\n")
# TODO(jkummerow): See if this is accurate enough in practice.
walltime = sample_count * samplerate_secs
print(f"wall time: {walltime:.3f} s") # Sample rate precision!
print("")
avg = vmsum / sample_count / 1024
reported_max /= 1024
observed_max /= 1024
print(f"average RSS: {avg:.2f} MB")
print(f"reported max: {reported_max:.2f} MB")
print(f"observed max: {observed_max:.2f} MB")
sys.exit(process.returncode)
if __name__ == "__main__":
Main()