event_selection_set.cpp revision afdb9cea28340e31142fd66a90c88ed8e18ebbfa 
1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "event_selection_set.h"
18
19#include <base/logging.h>
20#include <base/stringprintf.h>
21
22#include "environment.h"
23#include "event_attr.h"
24#include "event_type.h"
25#include "perf_regs.h"
26
27bool IsBranchSamplingSupported() {
28  const EventType* type = FindEventTypeByName("cpu-cycles");
29  if (type == nullptr) {
30    return false;
31  }
32  perf_event_attr attr = CreateDefaultPerfEventAttr(*type);
33  attr.sample_type |= PERF_SAMPLE_BRANCH_STACK;
34  attr.branch_sample_type = PERF_SAMPLE_BRANCH_ANY;
35  return IsEventAttrSupportedByKernel(attr);
36}
37
38bool IsDwarfCallChainSamplingSupported() {
39  const EventType* type = FindEventTypeByName("cpu-cycles");
40  if (type == nullptr) {
41    return false;
42  }
43  perf_event_attr attr = CreateDefaultPerfEventAttr(*type);
44  attr.sample_type |= PERF_SAMPLE_CALLCHAIN | PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER;
45  attr.exclude_callchain_user = 1;
46  attr.sample_regs_user = GetSupportedRegMask();
47  attr.sample_stack_user = 8192;
48  return IsEventAttrSupportedByKernel(attr);
49}
50
51bool EventSelectionSet::AddEventType(const EventTypeAndModifier& event_type_modifier) {
52  EventSelection selection;
53  selection.event_type_modifier = event_type_modifier;
54  selection.event_attr = CreateDefaultPerfEventAttr(event_type_modifier.event_type);
55  selection.event_attr.exclude_user = event_type_modifier.exclude_user;
56  selection.event_attr.exclude_kernel = event_type_modifier.exclude_kernel;
57  selection.event_attr.exclude_hv = event_type_modifier.exclude_hv;
58  selection.event_attr.exclude_host = event_type_modifier.exclude_host;
59  selection.event_attr.exclude_guest = event_type_modifier.exclude_guest;
60  selection.event_attr.precise_ip = event_type_modifier.precise_ip;
61  if (!IsEventAttrSupportedByKernel(selection.event_attr)) {
62    LOG(ERROR) << "Event type '" << event_type_modifier.name << "' is not supported by the kernel";
63    return false;
64  }
65  selections_.push_back(std::move(selection));
66  UnionSampleType();
67  return true;
68}
69
70// Union the sample type of different event attrs can make reading sample records in perf.data
71// easier.
72void EventSelectionSet::UnionSampleType() {
73  uint64_t sample_type = 0;
74  for (auto& selection : selections_) {
75    sample_type |= selection.event_attr.sample_type;
76  }
77  for (auto& selection : selections_) {
78    selection.event_attr.sample_type = sample_type;
79  }
80}
81
82void EventSelectionSet::SetEnableOnExec(bool enable) {
83  for (auto& selection : selections_) {
84    selection.event_attr.enable_on_exec = (enable ? 1 : 0);
85  }
86}
87
88bool EventSelectionSet::GetEnableOnExec() {
89  for (auto& selection : selections_) {
90    if (selection.event_attr.enable_on_exec == 0) {
91      return false;
92    }
93  }
94  return true;
95}
96
97void EventSelectionSet::SampleIdAll() {
98  for (auto& selection : selections_) {
99    selection.event_attr.sample_id_all = 1;
100  }
101}
102
103void EventSelectionSet::SetSampleFreq(uint64_t sample_freq) {
104  for (auto& selection : selections_) {
105    perf_event_attr& attr = selection.event_attr;
106    attr.freq = 1;
107    attr.sample_freq = sample_freq;
108  }
109}
110
111void EventSelectionSet::SetSamplePeriod(uint64_t sample_period) {
112  for (auto& selection : selections_) {
113    perf_event_attr& attr = selection.event_attr;
114    attr.freq = 0;
115    attr.sample_period = sample_period;
116  }
117}
118
119bool EventSelectionSet::SetBranchSampling(uint64_t branch_sample_type) {
120  if (branch_sample_type != 0 &&
121      (branch_sample_type & (PERF_SAMPLE_BRANCH_ANY | PERF_SAMPLE_BRANCH_ANY_CALL |
122                             PERF_SAMPLE_BRANCH_ANY_RETURN | PERF_SAMPLE_BRANCH_IND_CALL)) == 0) {
123    LOG(ERROR) << "Invalid branch_sample_type: 0x" << std::hex << branch_sample_type;
124    return false;
125  }
126  if (branch_sample_type != 0 && !IsBranchSamplingSupported()) {
127    LOG(ERROR) << "branch stack sampling is not supported on this device.";
128    return false;
129  }
130  for (auto& selection : selections_) {
131    perf_event_attr& attr = selection.event_attr;
132    if (branch_sample_type != 0) {
133      attr.sample_type |= PERF_SAMPLE_BRANCH_STACK;
134    } else {
135      attr.sample_type &= ~PERF_SAMPLE_BRANCH_STACK;
136    }
137    attr.branch_sample_type = branch_sample_type;
138  }
139  return true;
140}
141
142void EventSelectionSet::EnableFpCallChainSampling() {
143  for (auto& selection : selections_) {
144    selection.event_attr.sample_type |= PERF_SAMPLE_CALLCHAIN;
145  }
146}
147
148bool EventSelectionSet::EnableDwarfCallChainSampling(uint32_t dump_stack_size) {
149  if (!IsDwarfCallChainSamplingSupported()) {
150    LOG(ERROR) << "dwarf callchain sampling is not supported on this device.";
151    return false;
152  }
153  for (auto& selection : selections_) {
154    selection.event_attr.sample_type |=
155        PERF_SAMPLE_CALLCHAIN | PERF_SAMPLE_REGS_USER | PERF_SAMPLE_STACK_USER;
156    selection.event_attr.exclude_callchain_user = 1;
157    selection.event_attr.sample_regs_user = GetSupportedRegMask();
158    selection.event_attr.sample_stack_user = dump_stack_size;
159  }
160  return true;
161}
162
163void EventSelectionSet::SetInherit(bool enable) {
164  for (auto& selection : selections_) {
165    selection.event_attr.inherit = (enable ? 1 : 0);
166  }
167}
168
169bool EventSelectionSet::OpenEventFilesForAllCpus() {
170  return OpenEventFilesForThreadsOnAllCpus({-1});
171}
172
173bool EventSelectionSet::OpenEventFilesForThreads(const std::vector<pid_t>& threads) {
174  return OpenEventFiles(threads, {-1});
175}
176
177bool EventSelectionSet::OpenEventFilesForThreadsOnAllCpus(const std::vector<pid_t>& threads) {
178  std::vector<int> cpus = GetOnlineCpus();
179  if (cpus.empty()) {
180    return false;
181  }
182  return OpenEventFiles(threads, cpus);
183}
184
185bool EventSelectionSet::OpenEventFiles(const std::vector<pid_t>& threads,
186                                       const std::vector<int>& cpus) {
187  for (auto& selection : selections_) {
188    for (auto& tid : threads) {
189      size_t open_per_thread = 0;
190      for (auto& cpu : cpus) {
191        auto event_fd = EventFd::OpenEventFile(selection.event_attr, tid, cpu);
192        if (event_fd != nullptr) {
193          selection.event_fds.push_back(std::move(event_fd));
194          ++open_per_thread;
195        }
196      }
197      // As the online cpus can be enabled or disabled at runtime, we may not open event file for
198      // all cpus successfully. But we should open at least one cpu successfully.
199      if (open_per_thread == 0) {
200        PLOG(ERROR) << "failed to open perf event file for event_type "
201                    << selection.event_type_modifier.name << " for "
202                    << (tid == -1 ? "all threads" : android::base::StringPrintf(" thread %d", tid));
203        return false;
204      }
205    }
206  }
207  return true;
208}
209
210bool EventSelectionSet::EnableEvents() {
211  for (auto& selection : selections_) {
212    for (auto& event_fd : selection.event_fds) {
213      if (!event_fd->EnableEvent()) {
214        return false;
215      }
216    }
217  }
218  return true;
219}
220
221bool EventSelectionSet::ReadCounters(std::vector<CountersInfo>* counters) {
222  counters->clear();
223  for (auto& selection : selections_) {
224    CountersInfo counters_info;
225    counters_info.event_type = &selection.event_type_modifier;
226    for (auto& event_fd : selection.event_fds) {
227      CountersInfo::CounterInfo counter_info;
228      if (!event_fd->ReadCounter(&counter_info.counter)) {
229        return false;
230      }
231      counter_info.tid = event_fd->ThreadId();
232      counter_info.cpu = event_fd->Cpu();
233      counters_info.counters.push_back(counter_info);
234    }
235    counters->push_back(counters_info);
236  }
237  return true;
238}
239
240void EventSelectionSet::PreparePollForEventFiles(std::vector<pollfd>* pollfds) {
241  for (auto& selection : selections_) {
242    for (auto& event_fd : selection.event_fds) {
243      pollfd poll_fd;
244      event_fd->PreparePollForMmapData(&poll_fd);
245      pollfds->push_back(poll_fd);
246    }
247  }
248}
249
250bool EventSelectionSet::MmapEventFiles(size_t mmap_pages) {
251  for (auto& selection : selections_) {
252    for (auto& event_fd : selection.event_fds) {
253      if (!event_fd->MmapContent(mmap_pages)) {
254        return false;
255      }
256    }
257  }
258  return true;
259}
260
261static bool ReadMmapEventDataForFd(std::unique_ptr<EventFd>& event_fd,
262                                   std::function<bool(const char*, size_t)> callback,
263                                   bool* have_data) {
264  *have_data = false;
265  while (true) {
266    char* data;
267    size_t size = event_fd->GetAvailableMmapData(&data);
268    if (size == 0) {
269      break;
270    }
271    if (!callback(data, size)) {
272      return false;
273    }
274    *have_data = true;
275    event_fd->DiscardMmapData(size);
276  }
277  return true;
278}
279
280bool EventSelectionSet::ReadMmapEventData(std::function<bool(const char*, size_t)> callback) {
281  for (auto& selection : selections_) {
282    for (auto& event_fd : selection.event_fds) {
283      while (true) {
284        bool have_data;
285        if (!ReadMmapEventDataForFd(event_fd, callback, &have_data)) {
286          return false;
287        }
288        if (!have_data) {
289          break;
290        }
291      }
292    }
293  }
294  return true;
295}
296
297EventSelectionSet::EventSelection* EventSelectionSet::FindSelectionByType(
298    const EventTypeAndModifier& event_type_modifier) {
299  for (auto& selection : selections_) {
300    if (selection.event_type_modifier.name == event_type_modifier.name) {
301      return &selection;
302    }
303  }
304  return nullptr;
305}
306
307const perf_event_attr* EventSelectionSet::FindEventAttrByType(
308    const EventTypeAndModifier& event_type_modifier) {
309  EventSelection* selection = FindSelectionByType(event_type_modifier);
310  return (selection != nullptr) ? &selection->event_attr : nullptr;
311}
312
313const std::vector<std::unique_ptr<EventFd>>* EventSelectionSet::FindEventFdsByType(
314    const EventTypeAndModifier& event_type_modifier) {
315  EventSelection* selection = FindSelectionByType(event_type_modifier);
316  return (selection != nullptr) ? &selection->event_fds : nullptr;
317}
318