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#include "cpu.h"
#include "powerlib.h"
#include <sstream>
#include <errno.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#define SYSFS_FILES "/sys/devices/system/cpu/"
using namespace std;
CPU::CPU(int id) : _cpu_base(id)
{
ostringstream strstr;
strstr << SYSFS_FILES << "cpu" << _cpu_base << "/online";
ONLINE_FILE = strstr.str();
}
int CPU::enable()
{
if (online())
return 0;
pDebug(DBG_INFO, "Trying to enable CPU %d", _cpu_base);
if (!write_line(ONLINE_FILE.c_str(), "1")) {
pDebug(DBG_DEBUG, "Unable to open file: %s\n", ONLINE_FILE.c_str());
return -1;
}
pDebug(DBG_INFO, "Set CPU %d online", _cpu_base);
if (!online()) {
pDebug(DBG_WARN, "Onlined CPU, but request was not accepted: %s\n",
ONLINE_FILE.c_str());
return -1;
}
return 1;
}
int CPU::disable()
{
if (!online())
return 0;
if (_cpu_base == 0) {
pDebug(DBG_DEBUG, "CPU 0 can't be offlined.");
return -1;
}
pDebug(DBG_INFO, "Trying to disable CPU %d", _cpu_base);
if (!write_line(ONLINE_FILE.c_str(), "0")) {
pDebug(DBG_DEBUG, "Unable to open file: %s\n",
ONLINE_FILE.c_str());
return -1;
}
pDebug(DBG_INFO, "Set CPU %d offline", _cpu_base);
if (online()) {
pDebug(DBG_WARN, "Offlined CPU, but request was not accepted: %s\n",
ONLINE_FILE.c_str());
return -1;
}
return 1;
}
bool CPU::online()
{
if (!hotpluggable())
return true;
char online_str[2];
if (!read_line(ONLINE_FILE.c_str(), online_str, 2)) {
pDebug(DBG_DEBUG, "Unable to open file: %s\n", ONLINE_FILE.c_str());
return false;
}
int online = atoi(online_str);
if (!online)
return false;
return true;
}
bool CPU::hotpluggable()
{
if (access(ONLINE_FILE.c_str(), F_OK) < 0)
return false;
return true;
}
int CPU::enableAll()
{
// start with CPU 1, because CPU 0 is always online atm
int i = 1;
while (true) {
CPU cpu(i);
if (!cpu.hotpluggable())
break;
cpu.enable();
i++;
}
pDebug(DBG_DEBUG, "Found %d hotpluggable CPUs in system", i);
return i;
}
bool CPU::read_line(const char *filename, char *line, unsigned len)
{
FILE *fp = fopen(filename, "r");
if (!fp) {
pDebug(DBG_ERR, "Could not open '%s': %s", filename, strerror(errno));
return false;
}
if ((!fgets(line, len, fp))) {
pDebug(DBG_ERR, "Could not read from '%s': %s", filename, strerror(errno));
fclose(fp);
return false;
}
fclose(fp);
return true;
}
bool CPU::write_line(const char *filename, const char *fmt, ...)
{
FILE *fp = fopen(filename, "w+");
if (!fp) {
pDebug(DBG_WARN, "Could not open file for writing: %s; %s", filename, strerror(errno));
return false;
}
va_list ap;
va_start(ap, fmt); // get variable argument list passed
if (vfprintf(fp, fmt, ap) < 0) {
pDebug(DBG_WARN, "Could not write to file: %s", filename);
fclose(fp);
return false;
}
va_end(ap);
fclose(fp);
return true;
}
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