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linux: use /proc/cpuinfo for CPU frequency

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Obtain the CPU frequency from /proc/cpuinfo because there may not be any
cpufreq info available in /sys. This also means that the reported CPU speed
from now on is the *maximum* speed, not the *actual* speed the CPU runs at.

This change only applies to x86 because ARM and MIPS don't report that
information in /proc/cpuinfo.

Fixes #588.
This commit is contained in:
Ben Noordhuis 2012-10-20 23:58:22 +02:00
parent 1bb1ba27dd
commit 775064a3a5
1 changed files with 34 additions and 14 deletions
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48
src/unix/linux/linux-core.c
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@ -339,10 +339,13 @@ uv_err_t uv_cpu_info(uv_cpu_info_t** cpu_infos, int* count) {
if (ci == NULL) if (ci == NULL)
return uv__new_sys_error(ENOMEM); return uv__new_sys_error(ENOMEM);
read_speeds(numcpus, ci);
read_models(numcpus, ci); read_models(numcpus, ci);
read_times(numcpus, ci); read_times(numcpus, ci);
/* read_models() on x86 also reads the CPU speed from /proc/cpuinfo */
if (ci[0].speed == 0)
read_speeds(numcpus, ci);
*cpu_infos = ci; *cpu_infos = ci;
*count = numcpus; *count = numcpus;
@ -358,18 +361,26 @@ static void read_speeds(unsigned int numcpus, uv_cpu_info_t* ci) {
} }
/* Also reads the CPU frequency on x86. The other architectures only have
* a BogoMIPS field, which may not be very accurate.
*/
static void read_models(unsigned int numcpus, uv_cpu_info_t* ci) { static void read_models(unsigned int numcpus, uv_cpu_info_t* ci) {
#if defined(__i386__) || defined(__x86_64__) #if defined(__i386__) || defined(__x86_64__)
static const char marker[] = "model name\t: "; static const char model_marker[] = "model name\t: ";
static const char speed_marker[] = "cpu MHz\t\t: ";
#elif defined(__arm__) #elif defined(__arm__)
static const char marker[] = "Processor\t: "; static const char model_marker[] = "Processor\t: ";
static const char speed_marker[] = "";
#elif defined(__mips__) #elif defined(__mips__)
static const char marker[] = "cpu model\t\t: "; static const char model_marker[] = "cpu model\t\t: ";
static const char speed_marker[] = "";
#else #else
# warning uv_cpu_info() is not supported on this architecture. # warning uv_cpu_info() is not supported on this architecture.
static const char marker[] = "(dummy)"; static const char model_marker[] = "";
static const char speed_marker[] = "";
#endif #endif
unsigned int num; unsigned int model_idx;
unsigned int speed_idx;
char buf[1024]; char buf[1024];
char* model; char* model;
FILE* fp; FILE* fp;
@ -378,18 +389,27 @@ static void read_models(unsigned int numcpus, uv_cpu_info_t* ci) {
if (fp == NULL) if (fp == NULL)
return; return;
num = 0; model_idx = 0;
speed_idx = 0;
while (fgets(buf, sizeof(buf), fp)) { while (fgets(buf, sizeof(buf), fp)) {
if (num >= numcpus) if (model_marker[0] != '\0' &&
break; model_idx < numcpus &&
strncmp(buf, model_marker, sizeof(model_marker) - 1) == 0)
if (strncmp(buf, marker, sizeof(marker) - 1)) {
model = buf + sizeof(model_marker) - 1;
model = strndup(model, strlen(model) - 1); /* strip newline */
ci[model_idx++].model = model;
continue; continue;
}
model = buf + sizeof(marker) - 1; if (speed_marker[0] != '\0' &&
model = strndup(model, strlen(model) - 1); /* strip newline */ speed_idx < numcpus &&
ci[num++].model = model; strncmp(buf, speed_marker, sizeof(speed_marker) - 1) == 0)
{
ci[speed_idx++].speed = atoi(buf + sizeof(speed_marker) - 1);
continue;
}
} }
fclose(fp); fclose(fp);
} }