Yabin Cui | 67d3abd | 2015-04-16 15:26:31 -0700 | [diff] [blame] | 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_fd.h" |
| 18 | |
| 19 | #include <fcntl.h> |
| 20 | #include <stdio.h> |
| 21 | #include <sys/ioctl.h> |
| 22 | #include <sys/syscall.h> |
| 23 | #include <sys/types.h> |
| 24 | #include <memory> |
| 25 | |
| 26 | #include <base/logging.h> |
| 27 | #include <base/stringprintf.h> |
| 28 | |
| 29 | #include "event_type.h" |
| 30 | #include "event_attr.h" |
| 31 | #include "perf_event.h" |
| 32 | #include "utils.h" |
| 33 | |
| 34 | static int perf_event_open(perf_event_attr* attr, pid_t pid, int cpu, int group_fd, |
| 35 | unsigned long flags) { |
| 36 | return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags); |
| 37 | } |
| 38 | |
| 39 | std::unique_ptr<EventFd> EventFd::OpenEventFileForProcess(const EventAttr& attr, pid_t pid) { |
| 40 | return OpenEventFile(attr, pid, -1); |
| 41 | } |
| 42 | |
| 43 | std::unique_ptr<EventFd> EventFd::OpenEventFileForCpu(const EventAttr& attr, int cpu) { |
| 44 | return OpenEventFile(attr, -1, cpu); |
| 45 | } |
| 46 | |
| 47 | std::unique_ptr<EventFd> EventFd::OpenEventFile(const EventAttr& attr, pid_t pid, int cpu) { |
| 48 | perf_event_attr perf_attr = attr.Attr(); |
| 49 | std::string event_name = "unknown event"; |
| 50 | const EventType* event_type = |
| 51 | EventTypeFactory::FindEventTypeByConfig(perf_attr.type, perf_attr.config); |
| 52 | if (event_type != nullptr) { |
| 53 | event_name = event_type->name; |
| 54 | } |
| 55 | int perf_event_fd = perf_event_open(&perf_attr, pid, cpu, -1, 0); |
| 56 | if (perf_event_fd == -1) { |
| 57 | // It depends whether the perf_event_file configuration is supported by the kernel and the |
| 58 | // machine. So fail to open the file is not an error. |
| 59 | PLOG(DEBUG) << "open perf_event_file (event " << event_name << ", pid " << pid << ", cpu " |
| 60 | << cpu << ") failed"; |
| 61 | return nullptr; |
| 62 | } |
| 63 | if (fcntl(perf_event_fd, F_SETFD, FD_CLOEXEC) == -1) { |
| 64 | PLOG(ERROR) << "fcntl(FD_CLOEXEC) for perf_event_file (event " << event_name << ", pid " << pid |
| 65 | << ", cpu " << cpu << ") failed"; |
| 66 | return nullptr; |
| 67 | } |
| 68 | return std::unique_ptr<EventFd>(new EventFd(perf_event_fd, event_name, pid, cpu)); |
| 69 | } |
| 70 | |
| 71 | EventFd::~EventFd() { |
| 72 | close(perf_event_fd_); |
| 73 | } |
| 74 | |
| 75 | std::string EventFd::Name() const { |
| 76 | return android::base::StringPrintf("perf_event_file(event %s, pid %d, cpu %d)", |
| 77 | event_name_.c_str(), pid_, cpu_); |
| 78 | } |
| 79 | |
| 80 | bool EventFd::EnableEvent() { |
| 81 | int result = ioctl(perf_event_fd_, PERF_EVENT_IOC_ENABLE, 0); |
| 82 | if (result < 0) { |
| 83 | PLOG(ERROR) << "ioctl(enable) " << Name() << " failed"; |
| 84 | return false; |
| 85 | } |
| 86 | return true; |
| 87 | } |
| 88 | |
| 89 | bool EventFd::DisableEvent() { |
| 90 | int result = ioctl(perf_event_fd_, PERF_EVENT_IOC_DISABLE, 0); |
| 91 | if (result < 0) { |
| 92 | PLOG(ERROR) << "ioctl(disable) " << Name() << " failed"; |
| 93 | return false; |
| 94 | } |
| 95 | return true; |
| 96 | } |
Yabin Cui | 323e945 | 2015-04-20 18:07:17 -0700 | [diff] [blame] | 97 | |
| 98 | bool EventFd::ReadCounter(PerfCounter* counter) { |
| 99 | CHECK(counter != nullptr); |
| 100 | if (!ReadNBytesFromFile(perf_event_fd_, counter, sizeof(*counter))) { |
| 101 | PLOG(ERROR) << "ReadCounter from " << Name() << " failed"; |
| 102 | return false; |
| 103 | } |
| 104 | return true; |
| 105 | } |