File size: 13,748 Bytes
c61ccee
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import functools
import re
from collections import deque
from dataclasses import dataclass
from typing import Dict, List

from torch.autograd import _KinetoEvent
from torch.autograd.profiler import profile

from torch.profiler import DeviceType


def _traverse(tree, next_fn, children_fn=lambda x: x.children, reverse: bool = False):
    order = reversed if reverse else lambda x: x
    remaining = deque(order(tree))
    while remaining:
        curr_event = next_fn(remaining)
        yield curr_event
        for child_event in order(children_fn(curr_event)):
            remaining.append(child_event)


traverse_dfs = functools.partial(_traverse, next_fn=lambda x: x.pop(), reverse=True)
traverse_bfs = functools.partial(
    _traverse, next_fn=lambda x: x.popleft(), reverse=False
)


@dataclass
class EventMetrics:
    duration_time_ns: int = 0
    self_time_ns: int = 0
    idle_time_ns: int = 0
    queue_depth: int = 0

    @property
    def fraction_idle_time(self):
        if self.duration_time_ns == 0:
            return 0.0
        return self.idle_time_ns / self.duration_time_ns


@dataclass
class Interval:
    start: int
    end: int
    queue_depth: int = 0


class EventKey:
    def __init__(self, event):
        self.event = event

    def __hash__(self):
        return hash(self.event.id)

    def __eq__(self, other):
        return self.event.id == other.event.id

    def __repr__(self):
        return f"{self.event.name}"

    def intervals_overlap(self, intervals: List[Interval]):
        overlap_time = 0
        intervals = sorted(intervals, key=lambda x: x.start)

        if intervals:
            overlap_start = max(self.event.start_time_ns, intervals[0].start)
            overlap_end = min(self.event.end_time_ns, intervals[0].end)

            if overlap_start < overlap_end:
                overlap_time += overlap_end - overlap_start

        i, j = 0, 1
        while j < len(intervals):
            prev_interval = intervals[i]
            curr_interval = intervals[j]
            j += 1
            if prev_interval.end > curr_interval.start:
                # Completely subsumed by previous interval
                if prev_interval.end > curr_interval.end:
                    j += 1
                    continue
                else:
                    curr_interval.start = prev_interval.end
                    i = j

            overlap_start = max(self.event.start_time_ns, curr_interval.start)
            overlap_end = min(self.event.end_time_ns, curr_interval.end)
            if overlap_start < overlap_end:
                overlap_time += overlap_end - overlap_start

        return overlap_time


class BasicEvaluation:
    def __init__(self, prof: profile):
        self.profile = prof
        self.metrics: Dict[EventKey, EventMetrics] = {}
        self.compute_self_time()
        self.event_keys = sorted(
            (e for e in self.metrics.keys()), key=lambda x: x.event.start_time_ns
        )
        self.events = [e.event for e in self.event_keys]
        self.cuda_events: List[_KinetoEvent] = []
        self.queue_depth_list = self.compute_queue_depth()
        self.compute_idle_time()

    def compute_self_time(self):
        """

        Computes event's self time(total time - time in child ops).

        """
        assert self.profile.kineto_results is not None
        stack = deque(self.profile.kineto_results.experimental_event_tree())

        # standard iterating dfs
        while stack:
            curr_event = stack.pop()
            self_time = curr_event.duration_time_ns
            for child_event in curr_event.children:
                self_time -= child_event.duration_time_ns
                stack.append(child_event)
            assert (
                EventKey(curr_event) not in self.metrics
            ), f"Duplicate id: {curr_event.id}, {curr_event.name}"
            self.metrics[EventKey(curr_event)] = EventMetrics(self_time_ns=self_time)
            self.metrics[
                EventKey(curr_event)
            ].duration_time_ns = curr_event.duration_time_ns

    def compute_queue_depth(self):
        """

        Computes queue_depth at each event. This will calculate the queue depth data for

        All the events in the tree.

        This will return a list of Interval of queue depth data of cuda launch and kernels.

        """
        assert self.profile.kineto_results is not None
        cuda_event_list = self.profile.kineto_results.events()

        def is_cuda_launch_kernel(e):
            # TODO: find a better way to identify cudaLaunchKernel
            return e.name == "cudaLaunchKernel"

        def is_cuda_kernel(e):
            # TODO: find a better way to identify CUDA Kernel
            return e.device_type() == DeviceType.CUDA and "mem" not in e.name.lower()

        cuda_launch_events = sorted(
            (e for e in cuda_event_list if is_cuda_launch_kernel(e)),
            key=lambda x: x.start_us(),
        )
        cuda_kernel_events = sorted(
            (e for e in cuda_event_list if is_cuda_kernel(e)),
            key=lambda x: x.start_us(),
        )

        self.cuda_events = sorted(
            cuda_launch_events + cuda_kernel_events, key=lambda x: x.start_us()
        )

        kernel_mapping: Dict[_KinetoEvent, int] = {}
        last_mapped_kernel = 0
        for cuda_launch_event in cuda_launch_events:
            index = index_of_first_match(
                cuda_kernel_events,
                lambda x: x.linked_correlation_id()
                == cuda_launch_event.linked_correlation_id(),
                start=last_mapped_kernel,
            )
            kernel_mapping[cuda_launch_event] = index
            last_mapped_kernel = index if index is not None else last_mapped_kernel

        current_kernel_index = 0
        spawned_kernel_index = -1

        all_events = cuda_launch_events + cuda_kernel_events + self.events

        def new_old_event_comparator(event):
            if hasattr(event, "start_us"):
                return event.start_us() * 1000
            if hasattr(event, "start_time_ns"):
                return event.start_time_ns
            raise Exception("Unknown Event Type")

        queue_depth_list: List[Interval] = []
        all_events.sort(key=new_old_event_comparator)
        for event in all_events:
            # Find latest cuda kernel event
            if hasattr(event, "start_us"):
                start_time = event.start_us() * 1000
                end_time = (event.start_us() + event.duration_us()) * 1000
                # Find current spawned cuda kernel event
                if event in kernel_mapping and kernel_mapping[event] is not None:
                    spawned_kernel_index = kernel_mapping[event]
            elif hasattr(event, "start_time_ns"):
                start_time = event.start_time_ns  # type: ignore[attr-defined]
                end_time = event.end_time_ns  # type: ignore[attr-defined]

            while (
                current_kernel_index < len(cuda_kernel_events)
                and (cuda_kernel_events[current_kernel_index].start_us()) * 1000
                <= start_time  # type: ignore[possibly-undefined]
            ):
                current_kernel_index += 1
            current_queue_depth = spawned_kernel_index - current_kernel_index + 1
            current_queue_depth = max(current_queue_depth, 0)

            if hasattr(event, "start_us"):
                queue_depth_list.append(
                    Interval(start_time, end_time, current_queue_depth)  # type: ignore[possibly-undefined]
                )
            elif hasattr(event, "start_time_ns"):
                self.metrics[EventKey(event)].queue_depth = current_queue_depth

        return queue_depth_list

    def compute_idle_time(self):
        """

        Computes idle time of the profile.

        """
        # Based on queue_depth_list, we can calculate idle time for all the events
        idle = False
        idle_start = 0
        idle_intervals: List[Interval] = []
        if self.queue_depth_list and self.events:
            idle_intervals += [
                Interval(self.events[0].start_time_ns, self.queue_depth_list[0].start),
                Interval(self.queue_depth_list[-1].end, self.events[-1].end_time_ns),
            ]

        for data_point in self.queue_depth_list:
            if data_point.queue_depth == 0 and not idle:
                idle_start = data_point.end
                idle = True
            if data_point.queue_depth > 0 and idle:
                idle_intervals.append(Interval(idle_start, data_point.start))
                idle = False

        event_list = [e.event for e in self.metrics.keys()]
        for event in event_list:
            self.metrics[EventKey(event)].idle_time_ns = EventKey(
                event
            ).intervals_overlap(idle_intervals)

    def rank_events(self, length):
        """

        Filter and Rank the events based on some heuristics:

        1) Events that are in the falling phase of the queue depth.

        2) Events that have a high idle_time, self_time difference.



        Parameters:

            length: The number of events to return.

        """

        # Find the interval when qd is falling to 0
        import torch

        queue_depth_list = list(reversed(self.queue_depth_list))
        qd_values = [e.queue_depth for e in queue_depth_list]

        bottom_threashold = 0
        top_threashold = 4
        decrease_interval = []
        i = 0
        while i < len(qd_values):
            if qd_values[i] > bottom_threashold:
                i += 1
                continue
            for j in range(i + 1, len(qd_values)):
                # Find next zero and if the max value between them exceeds
                # the threshold, then we have a falling interval
                next_minimum_idx = index_of_first_match(
                    qd_values, lambda x: x <= bottom_threashold, start=j
                )
                peak_idx = argmax(qd_values, start=j, end=next_minimum_idx)

                # if is a valid peak, we add to list and continue
                if peak_idx is not None and qd_values[peak_idx] >= top_threashold:
                    decrease_interval.append(
                        Interval(
                            queue_depth_list[peak_idx].start, queue_depth_list[i].start
                        )
                    )
                    i = next_minimum_idx if next_minimum_idx is not None else i
                    break
            i += 1
        # Filter out events that are not in the decrease interval
        event_list = [
            event
            for event in self.metrics.keys()
            if event.intervals_overlap(decrease_interval)
        ]
        if event_list:
            self_time = torch.tensor(
                [self.metrics[event].self_time_ns for event in event_list],
                dtype=torch.float32,
            )
            idle_time = torch.tensor(
                [self.metrics[event].fraction_idle_time for event in event_list],
                dtype=torch.float32,
            )
            normalized_gain = (idle_time - torch.mean(idle_time)) / torch.std(idle_time)
            normalized_self = (self_time - torch.mean(self_time)) / torch.std(self_time)
            heuristic_score_list = normalized_gain + 0.6 * normalized_self

            # Sort events by heuristic
            event_list = [
                event
                for _, event in sorted(
                    zip(heuristic_score_list, event_list),
                    key=lambda x: x[0],
                    reverse=True,
                )
            ]
            event_list = event_list[:length]
        return event_list

    def get_optimizable_events(self, length: int = 1, print_enable: bool = True):
        event_list = self.rank_events(length)
        if not print_enable:
            return event_list
        output = "Optimizable events:\n" if event_list else "No events to optimize\n"

        output += "\n".join(
            [
                f"""{'-'*80}

Event:                {event}

Source code location: {source_code_location(event.event)}

Percentage idle time: {self.metrics[event].fraction_idle_time * 100:.2f}%

{'-'*80}"""
                for event in event_list
            ]
        )
        if print_enable:
            print(output)
        return event_list


def index_of_first_match(seq, predicate, start=0, end=None):
    if end is None or end >= len(seq):
        end = len(seq)
    for i in range(start, end):
        if predicate(seq[i]):
            return i
    return None


def argmax(seq, key=lambda x: x, start=0, end=None):
    seq = seq[start:end]
    if len(seq) == 0:
        return None
    return seq.index(max(seq, key=key)) + start


def source_code_location(event):
    while event is not None:
        match = re.search(r"\.py\(.*\)", event.name)
        if match is None:
            event = event.parent
            continue
        return event.name
    return "No source code location found"


# Provide an OSS workaround for cudagraphs + CUPTI issue
# https://github.com/pytorch/pytorch/issues/75504
# TODO(dberard) - deprecate / remove workaround for CUDA >= 12, when
# we stop supporting older CUDA versions.
def _init_for_cuda_graphs():
    from torch.autograd.profiler import profile

    with profile():
        pass