xref: /aosp_15_r20/external/pytorch/torch/csrc/instruction_counter/Module.cpp (revision da0073e96a02ea20f0ac840b70461e3646d07c45)
1 #include <torch/csrc/instruction_counter/Module.h>
2 #include <torch/csrc/utils/pybind.h>
3 #include <cerrno>
4 #include <cstdint>
5 #include <cstdio>
6 #include <cstdlib>
7 #include <cstring>
8 #include <stdexcept>
9 
10 #if defined(__linux__)
11 #include <linux/perf_event.h>
12 #include <sys/ioctl.h>
13 #include <sys/syscall.h>
14 #include <unistd.h>
15 #endif
16 
17 namespace torch::instruction_counter {
18 
start()19 long start() {
20 #if !defined(__linux__)
21   throw std::runtime_error("This systems seems not to be Linux");
22 #else
23 
24   // Construct base perf_event_attr struct
25   perf_event_attr attr{};
26   memset(&attr, 0, sizeof(attr));
27   attr.size = sizeof(attr);
28   attr.exclude_kernel = 1;
29   attr.disabled = 1;
30   attr.exclude_hv = 1;
31   attr.sample_period = 0;
32   // Enable hardware counting
33   attr.type = PERF_TYPE_HARDWARE;
34   attr.config = PERF_COUNT_HW_INSTRUCTIONS;
35 
36   long fd = syscall(SYS_perf_event_open, &attr, 0, -1, -1, 0);
37   if (fd == -1) {
38     fprintf(
39         stderr,
40         "Failed to open instruction count event: %s.\n",
41         strerror(errno));
42     return -1;
43   }
44   ioctl((int)fd, PERF_EVENT_IOC_RESET, 0); // Reset the counter
45   ioctl((int)fd, PERF_EVENT_IOC_ENABLE, 0); // Enable the counter
46   return fd;
47 #endif
48 }
49 
end(int fd)50 uint64_t end(int fd) {
51 #if !defined(__linux__)
52   throw std::runtime_error("This systems seems not to be Linux");
53 #else
54   // Disable the event group
55   if (ioctl(fd, PERF_EVENT_IOC_DISABLE, PERF_IOC_FLAG_GROUP) == -1) {
56     fprintf(
57         stderr,
58         "Error disabling perf event (fd: %d): %s\n",
59         fd,
60         strerror(errno));
61     return -1;
62   }
63 
64   uint64_t total_instructions = 0;
65 
66   // Read results
67   long ret_val = read(fd, &total_instructions, sizeof(total_instructions));
68   if (ret_val == -1) {
69     fprintf(stderr, "Error reading perf event results: %s\n", strerror(errno));
70     return -1;
71   }
72 
73   close(fd);
74   return total_instructions;
75 #endif
76 }
77 
initModule(PyObject * module)78 void initModule(PyObject* module) {
79   auto m = py::handle(module).cast<py::module>();
80   auto instruction_counter = m.def_submodule(
81       "_instruction_counter", "instruction_counter related pybind.");
82   instruction_counter.def("start", start);
83   instruction_counter.def("end", end);
84 }
85 
86 } // namespace torch::instruction_counter
87