File size: 3,249 Bytes
cf6b956 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 | #!/usr/bin/env python3
"""Map the hot instruction-fetch cache lines reported by drcachesim's histogram
tool onto functions of the traced binary.
The histogram tool reports instruction-fetch addresses at 64-byte cache-line
granularity, so this is a corroborating view of the traces themselves; the
exhaustive, instruction-exact attribution lives in
validation/steady_state/function_profile-segment-*.txt.
The binary is built -no-pie, so a runtime PC inside the main module equals its
link-time address and can be looked up directly in `nm` output; modules.log
(shipped in traces_simp/bin/) carries the base address of every module for the
general case.
Usage: trace_pc_funcs.py <histogram-output> <nm-file> [modules.log]
"""
import bisect
import re
import sys
from collections import defaultdict
def load_symbols(nm_path):
syms = []
for line in open(nm_path):
parts = line.split(None, 2)
if len(parts) < 3:
continue
addr, typ, name = parts[0], parts[1], parts[2].strip()
if typ.lower() not in ("t", "w", "i"):
continue
try:
syms.append((int(addr, 16), name))
except ValueError:
pass
syms.sort()
return [a for a, _ in syms], [n for _, n in syms]
def load_modules(path):
"""modules.log -> list of (base, end, name) for attribution of non-main PCs."""
mods = []
for line in open(path, errors="replace"):
fields = [f.strip() for f in line.split(",")]
if len(fields) < 6:
continue
try:
base = int(fields[2], 16) if fields[2].startswith("0x") else int(fields[2])
end = int(fields[3], 16) if fields[3].startswith("0x") else int(fields[3])
except ValueError:
continue
mods.append((base, end, fields[-1]))
return mods
def main():
hist_path, nm_path = sys.argv[1], sys.argv[2]
modules = load_modules(sys.argv[3]) if len(sys.argv) > 3 else []
addrs, names = load_symbols(nm_path)
lo, hi = addrs[0], addrs[-1] + 0x10000
per_func = defaultdict(int)
total = 0
in_instr_section = False
for line in open(hist_path):
if re.match(r"\s*icache top", line, re.I):
in_instr_section = True
continue
if re.match(r"\s*dcache top", line, re.I):
in_instr_section = False
continue
if not in_instr_section:
continue
m = re.match(r"\s*(0x[0-9a-fA-F]+)\s*:\s*([0-9]+)", line)
if not m:
continue
pc, cnt = int(m.group(1), 16), int(m.group(2))
total += cnt
if lo <= pc <= hi:
i = bisect.bisect_right(addrs, pc) - 1
per_func[names[i]] += cnt
else:
label = "[non-main module]"
for base, end, name in modules:
if base <= pc < end:
label = f"[{name}]"
break
per_func[label] += cnt
print(f"# hot instruction-fetch entries attributed: {total}")
print(f"{'share%':>8} {'count':>12} function")
for name, n in sorted(per_func.items(), key=lambda kv: -kv[1]):
print(f"{100.0 * n / total:8.3f} {n:12d} {name}")
if __name__ == "__main__":
main()
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