一，工具简介

xfsslower显示了XFS的读取、写入、打开和fsync操作，这些操作慢于一个阈值。

二，代码示例

#!/usr/bin/env python
from __future__ import print_function
from bcc import BPF
import argparse
from time import strftime
# arguments
examples = """examples:
    ./xfsslower             # trace operations slower than 10 ms (default)
    ./xfsslower 1           # trace operations slower than 1 ms
    ./xfsslower -j 1        # ... 1 ms, parsable output (csv)
    ./xfsslower 0           # trace all operations (warning: verbose)
    ./xfsslower -p 185      # trace PID 185 only
"""
parser = argparse.ArgumentParser(
    description="Trace common XFS file operations slower than a threshold",
    formatter_class=argparse.RawDescriptionHelpFormatter,
    epilog=examples)
parser.add_argument("-j", "--csv", action="store_true",
    help="just print fields: comma-separated values")
parser