5.56 BCC工具之funcslower.py解读

一，工具简介

funcslower主要可以���示内核或用户函数调用慢于既定阈值的情况。当基于聚合的工具失败时，它可以用于最后的诊断。

二，代码示例

#!/usr/bin/env pythonfrom __future__ import print_functionfrom bcc import BPFimport argparseimport timeexamples = """examples:  ./funcslower vfs_write        # trace vfs_write calls slower than 1ms  ./funcslower -m 10 vfs_write  # same, but slower than 10ms  ./funcslower -u 10 c:open     # trace open calls slower than 10us  ./funcslower -p 135 c:open    # trace pid 135 only  ./funcslower c:malloc c:free  # trace both malloc and free slower than 1ms  ./funcslower -a 2 c:open      # show first two arguments to open  ./funcslower -UK -m 10 c:open # Show user and kernel stack frame of open calls slower than 10ms  ./funcslower -f -UK c:open    # Output in folded format for flame graphs"""parser = argparse.ArgumentParser(    description="Trace slow kernel or user function calls.",    formatter_class