zephyr/scripts/profiling/stackcollapse.py

66 lines
1.8 KiB
Python

#!/usr/bin/env python3
#
# Copyright (c) 2023 KNS Group LLC (YADRO)
# Copyright (c) 2020 Yonatan Goldschmidt <yon.goldschmidt@gmail.com>
#
# SPDX-License-Identifier: Apache-2.0
"""
Stack compressor for FlameGraph
This translate stack samples captured by perf subsystem into format
used by flamegraph.pl. Translation uses .elf file to get function names
from addresses
Usage:
./script/perf/stackcollapse.py <file with perf printbuf output> <ELF file>
"""
import re
import sys
import struct
import binascii
from functools import lru_cache
from elftools.elf.elffile import ELFFile
@lru_cache(maxsize=None)
def addr_to_sym(addr, elf):
symtab = elf.get_section_by_name(".symtab")
for sym in symtab.iter_symbols():
if sym.entry.st_info.type == "STT_FUNC" and sym.entry.st_value <= addr < sym.entry.st_value + sym.entry.st_size:
return sym.name
if addr == 0:
return "nullptr"
return "[unknown]"
def collapse(buf, elf):
while buf:
count, = struct.unpack_from(">Q", buf)
assert count > 0
addrs = struct.unpack_from(f">{count}Q", buf, 8)
func_trace = reversed(list(map(lambda a: addr_to_sym(a, elf), addrs)))
prev_func = next(func_trace)
line = prev_func
# merge dublicate functions
for func in func_trace:
if prev_func != func:
prev_func = func
line += ";" + func
print(line, 1)
buf = buf[8 + 8 * count:]
if __name__ == "__main__":
elf = ELFFile(open(sys.argv[2], "rb"))
with open(sys.argv[1], "r") as f:
inp = f.read()
lines = inp.splitlines()
assert int(re.match(r"Perf buf length (\d+)", lines[0]).group(1)) == len(lines) - 1
buf = binascii.unhexlify("".join(lines[1:]))
collapse(buf, elf)