summaryrefslogtreecommitdiff
path: root/tools/perf/pmu-events/metric.py
blob: af58b74d16443859ab340ca1d4c274601cd236c1 (plain)
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
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
# SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
"""Parse or generate representations of perf metrics."""
import ast
import decimal
import json
import re
from typing import Dict, List, Optional, Set, Tuple, Union


class Expression:
  """Abstract base class of elements in a metric expression."""

  def ToPerfJson(self) -> str:
    """Returns a perf json file encoded representation."""
    raise NotImplementedError()

  def ToPython(self) -> str:
    """Returns a python expr parseable representation."""
    raise NotImplementedError()

  def Simplify(self):
    """Returns a simplified version of self."""
    raise NotImplementedError()

  def Equals(self, other) -> bool:
    """Returns true when two expressions are the same."""
    raise NotImplementedError()

  def Substitute(self, name: str, expression: 'Expression') -> 'Expression':
    raise NotImplementedError()

  def __str__(self) -> str:
    return self.ToPerfJson()

  def __or__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('|', self, other)

  def __ror__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('|', other, self)

  def __xor__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('^', self, other)

  def __and__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('&', self, other)

  def __rand__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('&', other, self)

  def __lt__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('<', self, other)

  def __gt__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('>', self, other)

  def __add__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('+', self, other)

  def __radd__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('+', other, self)

  def __sub__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('-', self, other)

  def __rsub__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('-', other, self)

  def __mul__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('*', self, other)

  def __rmul__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('*', other, self)

  def __truediv__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('/', self, other)

  def __rtruediv__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('/', other, self)

  def __mod__(self, other: Union[int, float, 'Expression']) -> 'Operator':
    return Operator('%', self, other)


def _Constify(val: Union[bool, int, float, Expression]) -> Expression:
  """Used to ensure that the nodes in the expression tree are all Expression."""
  if isinstance(val, bool):
    return Constant(1 if val else 0)
  if isinstance(val, (int, float)):
    return Constant(val)
  return val


# Simple lookup for operator precedence, used to avoid unnecessary
# brackets. Precedence matches that of the simple expression parser
# but differs from python where comparisons are lower precedence than
# the bitwise &, ^, | but not the logical versions that the expression
# parser doesn't have.
_PRECEDENCE = {
    '|': 0,
    '^': 1,
    '&': 2,
    '<': 3,
    '>': 3,
    '+': 4,
    '-': 4,
    '*': 5,
    '/': 5,
    '%': 5,
}


class Operator(Expression):
  """Represents a binary operator in the parse tree."""

  def __init__(self, operator: str, lhs: Union[int, float, Expression],
               rhs: Union[int, float, Expression]):
    self.operator = operator
    self.lhs = _Constify(lhs)
    self.rhs = _Constify(rhs)

  def Bracket(self,
              other: Expression,
              other_str: str,
              rhs: bool = False) -> str:
    """If necessary brackets the given other value.

    If ``other`` is an operator then a bracket is necessary when
    this/self operator has higher precedence. Consider: '(a + b) * c',
    ``other_str`` will be 'a + b'. A bracket is necessary as without
    the bracket 'a + b * c' will evaluate 'b * c' first. However, '(a
    * b) + c' doesn't need a bracket as 'a * b' will always be
    evaluated first. For 'a / (b * c)' (ie the same precedence level
    operations) then we add the bracket to best match the original
    input, but not for '(a / b) * c' where the bracket is unnecessary.

    Args:
      other (Expression): is a lhs or rhs operator
      other_str (str): ``other`` in the appropriate string form
      rhs (bool):  is ``other`` on the RHS

    Returns:
      str: possibly bracketed other_str
    """
    if isinstance(other, Operator):
      if _PRECEDENCE.get(self.operator, -1) > _PRECEDENCE.get(
          other.operator, -1):
        return f'({other_str})'
      if rhs and _PRECEDENCE.get(self.operator, -1) == _PRECEDENCE.get(
          other.operator, -1):
        return f'({other_str})'
    return other_str

  def ToPerfJson(self):
    return (f'{self.Bracket(self.lhs, self.lhs.ToPerfJson())} {self.operator} '
            f'{self.Bracket(self.rhs, self.rhs.ToPerfJson(), True)}')

  def ToPython(self):
    return (f'{self.Bracket(self.lhs, self.lhs.ToPython())} {self.operator} '
            f'{self.Bracket(self.rhs, self.rhs.ToPython(), True)}')

  def Simplify(self) -> Expression:
    lhs = self.lhs.Simplify()
    rhs = self.rhs.Simplify()
    if isinstance(lhs, Constant) and isinstance(rhs, Constant):
      return Constant(ast.literal_eval(lhs + self.operator + rhs))

    if isinstance(self.lhs, Constant):
      if self.operator in ('+', '|') and lhs.value == '0':
        return rhs

      # Simplify multiplication by 0 except for the slot event which
      # is deliberately introduced using this pattern.
      if self.operator == '*' and lhs.value == '0' and (
          not isinstance(rhs, Event) or 'slots' not in rhs.name.lower()):
        return Constant(0)

      if self.operator == '*' and lhs.value == '1':
        return rhs

    if isinstance(rhs, Constant):
      if self.operator in ('+', '|') and rhs.value == '0':
        return lhs

      if self.operator == '*' and rhs.value == '0':
        return Constant(0)

      if self.operator == '*' and self.rhs.value == '1':
        return lhs

    return Operator(self.operator, lhs, rhs)

  def Equals(self, other: Expression) -> bool:
    if isinstance(other, Operator):
      return self.operator == other.operator and self.lhs.Equals(
          other.lhs) and self.rhs.Equals(other.rhs)
    return False

  def Substitute(self, name: str, expression: Expression) -> Expression:
    if self.Equals(expression):
      return Event(name)
    lhs = self.lhs.Substitute(name, expression)
    rhs = None
    if self.rhs:
      rhs = self.rhs.Substitute(name, expression)
    return Operator(self.operator, lhs, rhs)


class Select(Expression):
  """Represents a select ternary in the parse tree."""

  def __init__(self, true_val: Union[int, float, Expression],
               cond: Union[int, float, Expression],
               false_val: Union[int, float, Expression]):
    self.true_val = _Constify(true_val)
    self.cond = _Constify(cond)
    self.false_val = _Constify(false_val)

  def ToPerfJson(self):
    true_str = self.true_val.ToPerfJson()
    cond_str = self.cond.ToPerfJson()
    false_str = self.false_val.ToPerfJson()
    return f'({true_str} if {cond_str} else {false_str})'

  def ToPython(self):
    return (f'Select({self.true_val.ToPython()}, {self.cond.ToPython()}, '
            f'{self.false_val.ToPython()})')

  def Simplify(self) -> Expression:
    cond = self.cond.Simplify()
    true_val = self.true_val.Simplify()
    false_val = self.false_val.Simplify()
    if isinstance(cond, Constant):
      return false_val if cond.value == '0' else true_val

    if true_val.Equals(false_val):
      return true_val

    return Select(true_val, cond, false_val)

  def Equals(self, other: Expression) -> bool:
    if isinstance(other, Select):
      return self.cond.Equals(other.cond) and self.false_val.Equals(
          other.false_val) and self.true_val.Equals(other.true_val)
    return False

  def Substitute(self, name: str, expression: Expression) -> Expression:
    if self.Equals(expression):
      return Event(name)
    true_val = self.true_val.Substitute(name, expression)
    cond = self.cond.Substitute(name, expression)
    false_val = self.false_val.Substitute(name, expression)
    return Select(true_val, cond, false_val)


class Function(Expression):
  """A function in an expression like min, max, d_ratio."""

  def __init__(self,
               fn: str,
               lhs: Union[int, float, Expression],
               rhs: Optional[Union[int, float, Expression]] = None):
    self.fn = fn
    self.lhs = _Constify(lhs)
    self.rhs = _Constify(rhs)

  def ToPerfJson(self):
    if self.rhs:
      return f'{self.fn}({self.lhs.ToPerfJson()}, {self.rhs.ToPerfJson()})'
    return f'{self.fn}({self.lhs.ToPerfJson()})'

  def ToPython(self):
    if self.rhs:
      return f'{self.fn}({self.lhs.ToPython()}, {self.rhs.ToPython()})'
    return f'{self.fn}({self.lhs.ToPython()})'

  def Simplify(self) -> Expression:
    lhs = self.lhs.Simplify()
    rhs = self.rhs.Simplify() if self.rhs else None
    if isinstance(lhs, Constant) and isinstance(rhs, Constant):
      if self.fn == 'd_ratio':
        if rhs.value == '0':
          return Constant(0)
        Constant(ast.literal_eval(f'{lhs} / {rhs}'))
      return Constant(ast.literal_eval(f'{self.fn}({lhs}, {rhs})'))

    return Function(self.fn, lhs, rhs)

  def Equals(self, other: Expression) -> bool:
    if isinstance(other, Function):
      result = self.fn == other.fn and self.lhs.Equals(other.lhs)
      if self.rhs:
        result = result and self.rhs.Equals(other.rhs)
      return result
    return False

  def Substitute(self, name: str, expression: Expression) -> Expression:
    if self.Equals(expression):
      return Event(name)
    lhs = self.lhs.Substitute(name, expression)
    rhs = None
    if self.rhs:
      rhs = self.rhs.Substitute(name, expression)
    return Function(self.fn, lhs, rhs)


def _FixEscapes(s: str) -> str:
  s = re.sub(r'([^\\]),', r'\1\\,', s)
  return re.sub(r'([^\\])=', r'\1\\=', s)


class Event(Expression):
  """An event in an expression."""

  def __init__(self, name: str, legacy_name: str = ''):
    self.name = _FixEscapes(name)
    self.legacy_name = _FixEscapes(legacy_name)

  def ToPerfJson(self):
    result = re.sub('/', '@', self.name)
    return result

  def ToPython(self):
    return f'Event(r"{self.name}")'

  def Simplify(self) -> Expression:
    return self

  def Equals(self, other: Expression) -> bool:
    return isinstance(other, Event) and self.name == other.name

  def Substitute(self, name: str, expression: Expression) -> Expression:
    return self


class Constant(Expression):
  """A constant within the expression tree."""

  def __init__(self, value: Union[float, str]):
    ctx = decimal.Context()
    ctx.prec = 20
    dec = ctx.create_decimal(repr(value) if isinstance(value, float) else value)
    self.value = dec.normalize().to_eng_string()
    self.value = self.value.replace('+', '')
    self.value = self.value.replace('E', 'e')

  def ToPerfJson(self):
    return self.value

  def ToPython(self):
    return f'Constant({self.value})'

  def Simplify(self) -> Expression:
    return self

  def Equals(self, other: Expression) -> bool:
    return isinstance(other, Constant) and self.value == other.value

  def Substitute(self, name: str, expression: Expression) -> Expression:
    return self


class Literal(Expression):
  """A runtime literal within the expression tree."""

  def __init__(self, value: str):
    self.value = value

  def ToPerfJson(self):
    return self.value

  def ToPython(self):
    return f'Literal({self.value})'

  def Simplify(self) -> Expression:
    return self

  def Equals(self, other: Expression) -> bool:
    return isinstance(other, Literal) and self.value == other.value

  def Substitute(self, name: str, expression: Expression) -> Expression:
    return self


def min(lhs: Union[int, float, Expression], rhs: Union[int, float,
                                                       Expression]) -> Function:
  # pylint: disable=redefined-builtin
  # pylint: disable=invalid-name
  return Function('min', lhs, rhs)


def max(lhs: Union[int, float, Expression], rhs: Union[int, float,
                                                       Expression]) -> Function:
  # pylint: disable=redefined-builtin
  # pylint: disable=invalid-name
  return Function('max', lhs, rhs)


def d_ratio(lhs: Union[int, float, Expression],
            rhs: Union[int, float, Expression]) -> Function:
  # pylint: disable=redefined-builtin
  # pylint: disable=invalid-name
  return Function('d_ratio', lhs, rhs)


def source_count(event: Event) -> Function:
  # pylint: disable=redefined-builtin
  # pylint: disable=invalid-name
  return Function('source_count', event)


class Metric:
  """An individual metric that will specifiable on the perf command line."""
  groups: Set[str]
  expr: Expression
  scale_unit: str
  constraint: bool

  def __init__(self,
               name: str,
               description: str,
               expr: Expression,
               scale_unit: str,
               constraint: bool = False):
    self.name = name
    self.description = description
    self.expr = expr.Simplify()
    # Workraound valid_only_metric hiding certain metrics based on unit.
    scale_unit = scale_unit.replace('/sec', ' per sec')
    if scale_unit[0].isdigit():
      self.scale_unit = scale_unit
    else:
      self.scale_unit = f'1{scale_unit}'
    self.constraint = constraint
    self.groups = set()

  def __lt__(self, other):
    """Sort order."""
    return self.name < other.name

  def AddToMetricGroup(self, group):
    """Callback used when being added to a MetricGroup."""
    self.groups.add(group.name)

  def Flatten(self) -> Set['Metric']:
    """Return a leaf metric."""
    return set([self])

  def ToPerfJson(self) -> Dict[str, str]:
    """Return as dictionary for Json generation."""
    result = {
        'MetricName': self.name,
        'MetricGroup': ';'.join(sorted(self.groups)),
        'BriefDescription': self.description,
        'MetricExpr': self.expr.ToPerfJson(),
        'ScaleUnit': self.scale_unit
    }
    if self.constraint:
      result['MetricConstraint'] = 'NO_NMI_WATCHDOG'

    return result


class _MetricJsonEncoder(json.JSONEncoder):
  """Special handling for Metric objects."""

  def default(self, o):
    if isinstance(o, Metric):
      return o.ToPerfJson()
    return json.JSONEncoder.default(self, o)


class MetricGroup:
  """A group of metrics.

  Metric groups may be specificd on the perf command line, but within
  the json they aren't encoded. Metrics may be in multiple groups
  which can facilitate arrangements similar to trees.
  """

  def __init__(self, name: str, metric_list: List[Union[Metric,
                                                        'MetricGroup']]):
    self.name = name
    self.metric_list = metric_list
    for metric in metric_list:
      metric.AddToMetricGroup(self)

  def AddToMetricGroup(self, group):
    """Callback used when a MetricGroup is added into another."""
    for metric in self.metric_list:
      metric.AddToMetricGroup(group)

  def Flatten(self) -> Set[Metric]:
    """Returns a set of all leaf metrics."""
    result = set()
    for x in self.metric_list:
      result = result.union(x.Flatten())

    return result

  def ToPerfJson(self) -> str:
    return json.dumps(sorted(self.Flatten()), indent=2, cls=_MetricJsonEncoder)

  def __str__(self) -> str:
    return self.ToPerfJson()


class _RewriteIfExpToSelect(ast.NodeTransformer):
  """Transformer to convert if-else nodes to Select expressions."""

  def visit_IfExp(self, node):
    # pylint: disable=invalid-name
    self.generic_visit(node)
    call = ast.Call(
        func=ast.Name(id='Select', ctx=ast.Load()),
        args=[node.body, node.test, node.orelse],
        keywords=[])
    ast.copy_location(call, node.test)
    return call


def ParsePerfJson(orig: str) -> Expression:
  """A simple json metric expression decoder.

  Converts a json encoded metric expression by way of python's ast and
  eval routine. First tokens are mapped to Event calls, then
  accidentally converted keywords or literals are mapped to their
  appropriate calls. Python's ast is used to match if-else that can't
  be handled via operator overloading. Finally the ast is evaluated.

  Args:
    orig (str): String to parse.

  Returns:
    Expression: The parsed string.
  """
  # pylint: disable=eval-used
  py = orig.strip()
  py = re.sub(r'([a-zA-Z][^-+/\* \\\(\),]*(?:\\.[^-+/\* \\\(\),]*)*)',
              r'Event(r"\1")', py)
  py = re.sub(r'#Event\(r"([^"]*)"\)', r'Literal("#\1")', py)
  py = re.sub(r'([0-9]+)Event\(r"(e[0-9]+)"\)', r'\1\2', py)
  keywords = ['if', 'else', 'min', 'max', 'd_ratio', 'source_count']
  for kw in keywords:
    py = re.sub(rf'Event\(r"{kw}"\)', kw, py)

  try:
    parsed = ast.parse(py, mode='eval')
  except SyntaxError as e:
    raise SyntaxError(f'Parsing expression:\n{orig}') from e
  _RewriteIfExpToSelect().visit(parsed)
  parsed = ast.fix_missing_locations(parsed)
  return _Constify(eval(compile(parsed, orig, 'eval')))


def RewriteMetricsInTermsOfOthers(metrics: List[Tuple[str, str, Expression]]
                                  )-> Dict[Tuple[str, str], Expression]:
  """Shorten metrics by rewriting in terms of others.

  Args:
    metrics (list): pmus, metric names and their expressions.
  Returns:
    Dict: mapping from a pmu, metric name pair to a shortened expression.
  """
  updates: Dict[Tuple[str, str], Expression] = dict()
  for outer_pmu, outer_name, outer_expression in metrics:
    if outer_pmu is None:
      outer_pmu = 'cpu'
    updated = outer_expression
    while True:
      for inner_pmu, inner_name, inner_expression in metrics:
        if inner_pmu is None:
          inner_pmu = 'cpu'
        if inner_pmu.lower() != outer_pmu.lower():
          continue
        if inner_name.lower() == outer_name.lower():
          continue
        if (inner_pmu, inner_name) in updates:
          inner_expression = updates[(inner_pmu, inner_name)]
        updated = updated.Substitute(inner_name, inner_expression)
      if updated.Equals(outer_expression):
        break
      if (outer_pmu, outer_name) in updates and updated.Equals(updates[(outer_pmu, outer_name)]):
        break
      updates[(outer_pmu, outer_name)] = updated
  return updates