/**
* Maintain profiles of a running stack.
*/
Profiler::Profiler(bool needCPUAffinity) : m_successful(true),
m_stack(nullptr),
m_frame_free_list(nullptr) {
if (!s_rand_initialized) {
s_rand_initialized = true;
srand(math_generate_seed());
}
if (needCPUAffinity) {
//
// Bind to a random cpu so that we can use rdtsc instruction.
//
int cur_cpu_id = rand() % s_machine.m_cpu_num;
GET_AFFINITY(0, sizeof(cpu_set_t), &m_prev_mask);
MachineInfo::BindToCPU(cur_cpu_id);
m_MHz = s_machine.m_cpu_frequencies[cur_cpu_id];
} else {
//
// Take cpu0's speed as a proxy for all cpus.
//
m_MHz = s_machine.m_cpu_frequencies[0];
}
memset(m_func_hash_counters, 0, sizeof(m_func_hash_counters));
}
Profiler() : m_successful(true), m_stack(NULL), m_frame_free_list(NULL) {
if (!s_rand_initialized) {
s_rand_initialized = true;
srand(GENERATE_SEED());
}
// bind to a random cpu so that we can use rdtsc instruction.
int cur_cpu_id = rand() % s_machine.m_cpu_num;
GET_AFFINITY(0, sizeof(cpu_set_t), &m_prev_mask);
MachineInfo::BindToCPU(cur_cpu_id);
m_MHz = s_machine.m_cpu_frequencies[cur_cpu_id];
memset(m_func_hash_counters, 0, sizeof(m_func_hash_counters));
}
MachineInfo() {
m_cpu_num = sysconf(_SC_NPROCESSORS_CONF);
m_cpu_frequencies = get_cpu_frequency_from_file("/proc/cpuinfo", m_cpu_num);
if (m_cpu_frequencies)
return;
m_cpu_frequencies = new int64_t[m_cpu_num];
for (int i = 0; i < m_cpu_num; i++) {
cpu_set_t prev_mask;
GET_AFFINITY(0, sizeof(cpu_set_t), &prev_mask);
BindToCPU(i);
// Make sure the current process gets scheduled to the target cpu. This
// might not be necessary though.
usleep(0);
m_cpu_frequencies[i] = get_cpu_frequency();
SET_AFFINITY(0, sizeof(cpu_set_t), &prev_mask);
}
}
