original_kernel/tools/power/cpupower/utils/helpers/topology.c

109 lines
2.9 KiB
C

/*
* (C) 2010,2011 Thomas Renninger <trenn@suse.de>, Novell Inc.
*
* Licensed under the terms of the GNU GPL License version 2.
*
* ToDo: Needs to be done more properly for AMD/Intel specifics
*/
/* Helper struct for qsort, must be in sync with cpupower_topology.cpu_info */
/* Be careful: Need to pass unsigned to the sort, so that offlined cores are
in the end, but double check for -1 for offlined cpus at other places */
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <helpers/helpers.h>
#include <helpers/sysfs.h>
/* returns -1 on failure, 0 on success */
int sysfs_topology_read_file(unsigned int cpu, const char *fname)
{
unsigned long value;
char linebuf[MAX_LINE_LEN];
char *endp;
char path[SYSFS_PATH_MAX];
snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/topology/%s",
cpu, fname);
if (sysfs_read_file(path, linebuf, MAX_LINE_LEN) == 0 )
return -1;
value = strtoul(linebuf, &endp, 0);
if ( endp == linebuf || errno == ERANGE )
return -1;
return value;
}
struct cpuid_core_info {
unsigned int pkg;
unsigned int thread;
unsigned int cpu;
};
static int __compare(const void *t1, const void *t2)
{
struct cpuid_core_info *top1 = (struct cpuid_core_info *)t1;
struct cpuid_core_info *top2 = (struct cpuid_core_info *)t2;
if (top1->pkg < top2->pkg)
return -1;
else if (top1->pkg > top2->pkg)
return 1;
else if (top1->thread < top2->thread)
return -1;
else if (top1->thread > top2->thread)
return 1;
else if (top1->cpu < top2->cpu)
return -1;
else if (top1->cpu > top2->cpu)
return 1;
else
return 0;
}
/*
* Returns amount of cpus, negative on error, cpu_top must be
* passed to cpu_topology_release to free resources
*
* Array is sorted after ->pkg, ->core, then ->cpu
*/
int get_cpu_topology(struct cpupower_topology *cpu_top)
{
int cpu, cpus = sysconf(_SC_NPROCESSORS_CONF);
cpu_top->core_info = malloc(sizeof(struct cpupower_topology) * cpus);
if (cpu_top->core_info == NULL)
return -ENOMEM;
cpu_top->pkgs = cpu_top->cores = 0;
for (cpu = 0; cpu < cpus; cpu++) {
cpu_top->core_info[cpu].pkg =
sysfs_topology_read_file(cpu, "physical_package_id");
if ((int)cpu_top->core_info[cpu].pkg != -1 &&
cpu_top->core_info[cpu].pkg > cpu_top->pkgs)
cpu_top->pkgs = cpu_top->core_info[cpu].pkg;
cpu_top->core_info[cpu].core =
sysfs_topology_read_file(cpu, "core_id");
cpu_top->core_info[cpu].cpu = cpu;
}
cpu_top->pkgs++;
qsort(cpu_top->core_info, cpus, sizeof(struct cpuid_core_info),
__compare);
/* Intel's cores count is not consecutively numbered, there may
* be a core_id of 3, but none of 2. Assume there always is 0
* Get amount of cores by counting duplicates in a package
for (cpu = 0; cpu_top->core_info[cpu].pkg = 0 && cpu < cpus; cpu++) {
if (cpu_top->core_info[cpu].core == 0)
cpu_top->cores++;
*/
return cpus;
}
void cpu_topology_release(struct cpupower_topology cpu_top)
{
free(cpu_top.core_info);
}