diff --git a/scripts/profiling/stackcollapse.py b/scripts/profiling/stackcollapse.py new file mode 100644 index 00000000000..38088527fca --- /dev/null +++ b/scripts/profiling/stackcollapse.py @@ -0,0 +1,65 @@ +#!/usr/bin/env python3 +# +# Copyright (c) 2023 KNS Group LLC (YADRO) +# Copyright (c) 2020 Yonatan Goldschmidt +# +# 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 +""" + +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)