![Thomas Renninger](/assets/img/avatar_default.png)
Before, checking for offlined CPUs was done dirty and it was checked whether topology parsing returned -1 values. But this is a valid case on a Xen (and possibly other) kernels. Do proper online/offline checking, also take CONFIG_HOTPLUG_CPU option into account (no /sys/devices/../cpuX/online file). Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
112 lines
3 KiB
C
112 lines
3 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;
|
|
/* flags */
|
|
unsigned int is_online:1;
|
|
};
|
|
|
|
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].cpu = cpu;
|
|
cpu_top->core_info[cpu].is_online = sysfs_is_cpu_online(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->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);
|
|
}
|