mirror of
https://github.com/bherbruck/solidcraft.git
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Thijs Damsma
af94851172
- UnitResult.timing (not in the report): wall time of case building,
run_cpp, run_rust, compare and the slowest Rust case; main prints
`TIME <unit> ...` to stderr per unit
- DIFFTEST_RUST_DIGEST=<dir>: writes <dir>/<unit>.digest with one
`<case>\t<fnv1a64 of format!("{rust_output:?}")>` line per case, so two
builds can be proved bit-identical; off by default
- README: --green takes ~35 min on 16 threads (not ~2 min), TIME line,
digest, and scripts/perf (ptrace sampler + analyzer, no sudo needed)
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01H9QwJFBTKLZ9FFK3nVd1X4
94 lines
3.0 KiB
Python
94 lines
3.0 KiB
Python
#!/usr/bin/env python3
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"""Poor man's sampling profiler: ptrace + frame-pointer unwinding (x86_64 Linux).
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No perf_event needed (perf_event_paranoid=2 blocks samply). The target is our own
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child (PTRACE_TRACEME), so yama ptrace_scope=1 allows it. Build the target with
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`-C force-frame-pointers=yes` and debug line tables.
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usage: sampler.py OUT.json INTERVAL_MS -- cmd args...
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Writes {"maps": [...], "samples": [[addr, ...], ...]} (innermost first).
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"""
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import ctypes
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import json
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import os
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import signal
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import struct
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import sys
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import time
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libc = ctypes.CDLL(None, use_errno=True)
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libc.ptrace.restype = ctypes.c_long
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libc.ptrace.argtypes = [ctypes.c_long, ctypes.c_long, ctypes.c_void_p, ctypes.c_void_p]
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PTRACE_TRACEME, PTRACE_CONT, PTRACE_GETREGS, PTRACE_SETOPTIONS = 0, 7, 12, 0x4200
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PTRACE_O_EXITKILL = 0x100000
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class Regs(ctypes.Structure):
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_fields_ = [(n, ctypes.c_ulonglong) for n in (
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"r15 r14 r13 r12 rbp rbx r11 r10 r9 r8 rax rcx rdx rsi rdi orig_rax rip cs "
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"eflags rsp ss fs_base gs_base ds es fs gs").split()]
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def main():
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out, interval = sys.argv[1], float(sys.argv[2]) / 1000.0
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cmd = sys.argv[sys.argv.index("--") + 1:]
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pid = os.fork()
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if pid == 0:
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libc.ptrace(PTRACE_TRACEME, 0, None, None)
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os.execvp(cmd[0], cmd)
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_, st = os.waitpid(pid, 0) # exec SIGTRAP stop
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libc.ptrace(PTRACE_SETOPTIONS, pid, None, ctypes.c_void_p(PTRACE_O_EXITKILL))
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libc.ptrace(PTRACE_CONT, pid, None, None)
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mem = os.open(f"/proc/{pid}/mem", os.O_RDONLY)
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samples, maps = [], None
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regs = Regs()
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while True:
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time.sleep(interval)
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try:
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os.kill(pid, signal.SIGSTOP)
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except ProcessLookupError:
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break
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# Wait for our SIGSTOP; forward any other signal.
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done = False
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while True:
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_, st = os.waitpid(pid, 0)
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if os.WIFEXITED(st) or os.WIFSIGNALED(st):
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done = True
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break
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sig = os.WSTOPSIG(st)
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if sig == signal.SIGSTOP:
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break
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libc.ptrace(PTRACE_CONT, pid, None, ctypes.c_void_p(sig))
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if done:
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break
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if maps is None:
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with open(f"/proc/{pid}/maps") as f:
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maps = f.read()
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libc.ptrace(PTRACE_GETREGS, pid, None, ctypes.byref(regs))
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stack = [regs.rip]
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fp = regs.rbp
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for _ in range(512):
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if fp == 0 or fp & 7 or fp >= (1 << 47):
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break
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try:
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b = os.pread(mem, 16, fp)
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except OSError:
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break
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if len(b) < 16:
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break
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nfp, ret = struct.unpack("<QQ", b)
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if ret == 0:
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break
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stack.append(ret)
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if nfp <= fp:
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break
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fp = nfp
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samples.append(stack)
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libc.ptrace(PTRACE_CONT, pid, None, None)
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with open(out, "w") as f:
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json.dump({"maps": maps or "", "samples": samples, "exe": cmd[0]}, f)
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print(f"sampler: {len(samples)} samples -> {out}", file=sys.stderr)
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main()
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