scripts/trace: parse and generate usdt bpftrace scripts
This patch introduces definitions responsible for generating bpftrace scripts and parsing its output. That output will be used in subsequent patches to provide annotations for SPDK traces. The script has a hardcoded set of probe points that are used to generate the bpftrace script. They're also checked against the probes present in code to sanitize them and make sure that they're in sync. Signed-off-by: Konrad Sztyber <konrad.sztyber@intel.com> Change-Id: I1b8c95e1a035bd7affed2c44b056828a5da94abd Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/8106 Tested-by: SPDK CI Jenkins <sys_sgci@intel.com> Reviewed-by: Jim Harris <james.r.harris@intel.com> Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
This commit is contained in:
Konrad Sztyber
Tomasz Zawadzki
parent
109af0bcb3
commit
01ae68f71d
@ -4,7 +4,129 @@ from argparse import ArgumentParser
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from dataclasses import dataclass
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from typing import Dict, List, TypeVar
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import json
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import os
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import re
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import subprocess
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import sys
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import tempfile
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@dataclass
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class DTraceArgument:
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"""Describes a DTrace probe (usdt) argument"""
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name: str
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pos: int
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type: type
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@dataclass
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class DTraceProbe:
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"""Describes a DTrace probe (usdt) point"""
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name: str
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args: Dict[str, DTraceArgument]
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def __init__(self, name, args):
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self.name = name
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self.args = {a.name: a for a in args}
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@dataclass
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class DTraceEntry:
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"""Describes a single DTrace probe invocation"""
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name: str
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args: Dict[str, TypeVar('ArgumentType', str, int)]
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def __init__(self, probe, args):
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valmap = {int: lambda x: int(x, 16),
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str: lambda x: x.strip().strip("'")}
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self.name = probe.name
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self.args = {}
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for name, value in args.items():
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arg = probe.args.get(name)
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if arg is None:
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raise ValueError(f'Unexpected argument: {name}')
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self.args[name] = valmap[arg.type](value)
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class DTrace:
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"""Generates bpftrace script based on the supplied probe points, parses its
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output and stores is as a list of DTraceEntry sorted by their tsc.
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"""
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def __init__(self, probes, file=None):
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self._avail_probes = self._list_probes()
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self._probes = {p.name: p for p in probes}
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self.entries = self._parse(file) if file is not None else []
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# Sanitize the probe definitions
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for probe in probes:
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if probe.name not in self._avail_probes:
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raise ValueError(f'Couldn\'t find probe: "{probe.name}"')
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for arg in probe.args.values():
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if arg.pos >= self._avail_probes[probe.name]:
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raise ValueError('Invalid probe argument position')
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if arg.type not in (int, str):
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raise ValueError('Invalid argument type')
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def _parse(self, file):
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regex = re.compile(r'(\w+): (.*)')
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entries = []
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for line in file.readlines():
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match = regex.match(line)
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if match is None:
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continue
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name, args = match.groups()
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probe = self._probes.get(name)
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# Skip the line if we don't recognize the probe name
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if probe is None:
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continue
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entries.append(DTraceEntry(probe, args=dict(a.strip().split('=')
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for a in args.split(','))))
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entries.sort(key=lambda e: e.args['tsc'])
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return entries
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def _list_probes(self):
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files = subprocess.check_output(['git', 'ls-files', '*.[ch]',
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':!:include/spdk_internal/usdt.h'])
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files = filter(lambda f: len(f) > 0, str(files, 'ascii').split('\n'))
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regex = re.compile(r'SPDK_DTRACE_PROBE([0-9]*)\((\w+)')
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probes = {}
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for fname in files:
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with open(fname, 'r') as file:
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for match in regex.finditer(file.read()):
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nargs, name = match.group(1), match.group(2)
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nargs = int(nargs) if len(nargs) > 0 else 0
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# Add one to accommodate for the tsc being the first arg
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probes[name] = nargs + 1
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return probes
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def _gen_usdt(self, probe):
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usdt = (f'usdt:__EXE__:{probe.name} {{' +
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f'printf("{probe.name}: ')
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args = probe.args
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if len(args) > 0:
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argtype = {int: '0x%lx', str: '\'%s\''}
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argcast = {int: lambda x: x, str: lambda x: f'str({x})'}
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argstr = [f'{a.name}={argtype[a.type]}' for a in args.values()]
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argval = [f'{argcast[a.type](f"arg{a.pos}")}' for a in args.values()]
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usdt += ', '.join(argstr) + '\\n", ' + ', '.join(argval)
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else:
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usdt += '\\n"'
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usdt += ');}'
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return usdt
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def generate(self):
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return '\n'.join([self._gen_usdt(p) for p in self._probes.values()])
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def record(self, pid):
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with tempfile.NamedTemporaryFile(mode='w+') as script:
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script.write(self.generate())
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script.flush()
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try:
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subprocess.run([f'{os.path.dirname(__file__)}/../bpftrace.sh',
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f'{pid}', f'{script.name}'])
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except KeyboardInterrupt:
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pass
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@dataclass
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@ -101,14 +223,42 @@ class Trace:
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print(' '.join([*filter(lambda f: f is not None, fields)]).rstrip())
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def build_dtrace():
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return DTrace([
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DTraceProbe(
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name='nvmf_poll_group_add_qpair',
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args=[DTraceArgument(name='tsc', pos=0, type=int),
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DTraceArgument(name='qpair', pos=1, type=int),
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DTraceArgument(name='thread', pos=2, type=int)]),
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DTraceProbe(
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name='nvmf_poll_group_remove_qpair',
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args=[DTraceArgument(name='tsc', pos=0, type=int),
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DTraceArgument(name='qpair', pos=1, type=int),
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DTraceArgument(name='thread', pos=2, type=int)]),
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DTraceProbe(
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name='nvmf_ctrlr_add_qpair',
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args=[DTraceArgument(name='tsc', pos=0, type=int),
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DTraceArgument(name='qpair', pos=1, type=int),
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DTraceArgument(name='qid', pos=2, type=int),
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DTraceArgument(name='subnqn', pos=3, type=str),
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DTraceArgument(name='hostnqn', pos=4, type=str)])])
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def main(argv):
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parser = ArgumentParser(description='SPDK trace annotation script')
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parser.add_argument('-i', '--input',
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help='JSON-formatted trace file produced by spdk_trace app')
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parser.add_argument('-g', '--generate', help='Generate bpftrace script', action='store_true')
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parser.add_argument('-r', '--record', help='Record BPF traces on PID', metavar='PID', type=int)
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args = parser.parse_args(argv)
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file = open(args.input, 'r') if args.input is not None else sys.stdin
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Trace(file).print()
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if args.generate:
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print(build_dtrace().generate())
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elif args.record:
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build_dtrace().record(args.record)
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else:
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file = open(args.input, 'r') if args.input is not None else sys.stdin
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Trace(file).print()
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if __name__ == '__main__':
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