Estimate private memory usage of a list of processes

private-memory-stats.py

import os
import sys


def process_private_memory(pid):
    smaps_path = f"/proc/{pid}/smaps"
    total = 0
    for line in open(smaps_path, 'r'):
        field, val = [val.strip() for val in line.split(':')]
        if field != "Private_Dirty":
            continue

        amount, unit = [field.strip() for field in val.split(" ")]
        amount = int(amount)

        if unit == "kB":
            scale = 1024
        else:
            # TODO - Handle other units if encountered.
            raise Exception(f"Unknown unit {unit}")

        total += amount * scale
    return total


def process_cmdline(pid):
    cmd = open(f"/proc/{pid}/comm", "r").read().strip()
    args = open(f"/proc/{pid}/cmdline", "r").read().strip().split("\x00")
    return f"{' '.join(args)}".strip()


pids = [pid for pid in sys.argv[1:] if os.path.exists(f"/proc/{pid}/comm")]
stats = [(pid, process_cmdline(pid), process_private_memory(pid) / (1024*1024)) for pid in pids]
stats = sorted(stats, key=lambda stats: stats[2])

system_total = 0
for pid, cmdline, private_mbs in stats:
    system_total += private_mbs
    print(f"{pid},{cmdline},{private_mbs}")

print(f"System total: {system_total}")

Derived from https://stackoverflow.com/a/16597463/434243