Commit d0e4a193 authored by Prarit Bhargava's avatar Prarit Bhargava Committed by Rafael J. Wysocki

tools/power/cpupower: allow running without cpu0

Linux-3.7 added CONFIG_BOOTPARAM_HOTPLUG_CPU0,
allowing systems to offline cpu0.

But when cpu0 is offline, cpupower monitor will not display all
processor and Mperf information:

[root@intel-skylake-dh-03 cpupower]# ./cpupower monitor
WARNING: at least one cpu is offline
    |Idle_Stats
CPU | POLL | C1-S | C1E- | C3-S | C6-S | C7s- | C8-S
   4|  0.00|  0.00|  0.00|  0.00|  0.90|  0.00| 96.13
   1|  0.00|  0.00|  5.49|  0.00|  0.01|  0.00| 92.26
   5|  0.00|  0.00|  0.00|  0.00|  0.46|  0.00| 99.50
   2| 45.42|  0.00|  0.00|  0.00| 22.94|  0.00| 28.84
   6|  0.00| 37.54|  0.00|  0.00|  0.00|  0.00|  0.00
   3|  0.00|  0.00|  0.00|  0.00|  0.30|  0.00| 91.99
   7|  0.00|  0.00|  0.00|  0.00|  4.70|  0.00|  0.70

This patch replaces the hard-coded use of cpu0 in cpupower with the
current cpu, allowing it to run without a cpu0.

After the patch is applied,

[root@intel-skylake-dh-03 cpupower]# ./cpupower monitor
WARNING: at least one cpu is offline
    |Nehalem                    || Mperf              || Idle_Stats
CPU | C3   | C6   | PC3  | PC6  || C0   | Cx   | Freq || POLL | C1-S | C1E- | C3-S | C6-S | C7s- | C8-S
   4|  0.01|  1.27|  0.00|  0.00||  0.04| 99.96|  3957||  0.00|  0.00|  0.00|  0.00|  1.43|  0.00| 98.52
   1|  0.00| 98.82|  0.00|  0.00||  0.05| 99.95|  3361||  0.00|  0.00|  0.01|  0.00|  0.03|  0.00| 99.88
   5|  0.00| 98.82|  0.00|  0.00||  0.09| 99.91|  3917||  0.00|  0.00|  0.00|  0.00| 99.38|  0.00|  0.50
   2|  0.33|  0.00|  0.00|  0.00||  0.00|100.00|  3890||  0.00|  0.00|  0.00|  0.00|  0.00|  0.00|100.00
   6|  0.33|  0.00|  0.00|  0.00||  0.01| 99.99|  3903||  0.00|  0.00|  0.00|  0.00|  0.00|  0.00| 99.99
   3|  0.01|  0.71|  0.00|  0.00||  0.06| 99.94|  3678||  0.00|  0.00|  0.00|  0.00|  0.80|  0.00| 99.13
   7|  0.01|  0.71|  0.00|  0.00||  0.03| 99.97|  3538||  0.00|  0.69| 11.70|  0.00|  0.00|  0.00| 87.57

There are some minor cleanups included in this patch.
Signed-off-by: default avatarPrarit Bhargava <prarit@redhat.com>
Signed-off-by: default avatarThomas Renninger <trenn@suse.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 2158e724
......@@ -12,6 +12,7 @@
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sched.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/utsname.h>
......@@ -31,6 +32,7 @@ static int cmd_help(int argc, const char **argv);
*/
struct cpupower_cpu_info cpupower_cpu_info;
int run_as_root;
int base_cpu;
/* Affected cpus chosen by -c/--cpu param */
struct bitmask *cpus_chosen;
......@@ -174,6 +176,7 @@ int main(int argc, const char *argv[])
unsigned int i, ret;
struct stat statbuf;
struct utsname uts;
char pathname[32];
cpus_chosen = bitmask_alloc(sysconf(_SC_NPROCESSORS_CONF));
......@@ -198,17 +201,23 @@ int main(int argc, const char *argv[])
argv[0] = cmd = "help";
}
get_cpu_info(0, &cpupower_cpu_info);
base_cpu = sched_getcpu();
if (base_cpu < 0) {
fprintf(stderr, _("No valid cpus found.\n"));
return EXIT_FAILURE;
}
get_cpu_info(&cpupower_cpu_info);
run_as_root = !geteuid();
if (run_as_root) {
ret = uname(&uts);
sprintf(pathname, "/dev/cpu/%d/msr", base_cpu);
if (!ret && !strcmp(uts.machine, "x86_64") &&
stat("/dev/cpu/0/msr", &statbuf) != 0) {
stat(pathname, &statbuf) != 0) {
if (system("modprobe msr") == -1)
fprintf(stderr, _("MSR access not available.\n"));
}
}
for (i = 0; i < ARRAY_SIZE(commands); i++) {
struct cmd_struct *p = commands + i;
......
......@@ -42,7 +42,7 @@ cpuid_func(edx);
*
* TBD: Should there be a cpuid alternative for this if /proc is not mounted?
*/
int get_cpu_info(unsigned int cpu, struct cpupower_cpu_info *cpu_info)
int get_cpu_info(struct cpupower_cpu_info *cpu_info)
{
FILE *fp;
char value[64];
......@@ -70,7 +70,7 @@ int get_cpu_info(unsigned int cpu, struct cpupower_cpu_info *cpu_info)
if (!strncmp(value, "processor\t: ", 12))
sscanf(value, "processor\t: %u", &proc);
if (proc != cpu)
if (proc != (unsigned int)base_cpu)
continue;
/* Get CPU vendor */
......
......@@ -34,6 +34,7 @@
/* Internationalization ****************************/
extern int run_as_root;
extern int base_cpu;
extern struct bitmask *cpus_chosen;
/* Global verbose (-d) stuff *********************************/
......@@ -87,11 +88,11 @@ struct cpupower_cpu_info {
*
* Extract CPU vendor, family, model, stepping info from /proc/cpuinfo
*
* Returns 0 on success or a negativ error code
* Returns 0 on success or a negative error code
* Only used on x86, below global's struct values are zero/unknown on
* other archs
*/
extern int get_cpu_info(unsigned int cpu, struct cpupower_cpu_info *cpu_info);
extern int get_cpu_info(struct cpupower_cpu_info *cpu_info);
extern struct cpupower_cpu_info cpupower_cpu_info;
/* cpuid and cpuinfo helpers **************************/
......
......@@ -13,7 +13,7 @@ int cpufreq_has_boost_support(unsigned int cpu, int *support, int *active,
*support = *active = *states = 0;
ret = get_cpu_info(0, &cpu_info);
ret = get_cpu_info(&cpu_info);
if (ret)
return ret;
......
......@@ -123,7 +123,7 @@ static int hsw_ext_start(void)
previous_count[num][cpu] = val;
}
}
hsw_ext_get_count(TSC, &tsc_at_measure_start, 0);
hsw_ext_get_count(TSC, &tsc_at_measure_start, base_cpu);
return 0;
}
......@@ -132,7 +132,7 @@ static int hsw_ext_stop(void)
unsigned long long val;
int num, cpu;
hsw_ext_get_count(TSC, &tsc_at_measure_end, 0);
hsw_ext_get_count(TSC, &tsc_at_measure_end, base_cpu);
for (num = 0; num < HSW_EXT_CSTATE_COUNT; num++) {
for (cpu = 0; cpu < cpu_count; cpu++) {
......
......@@ -80,7 +80,8 @@ static int *is_valid;
static int mperf_get_tsc(unsigned long long *tsc)
{
int ret;
ret = read_msr(0, MSR_TSC, tsc);
ret = read_msr(base_cpu, MSR_TSC, tsc);
if (ret)
dprint("Reading TSC MSR failed, returning %llu\n", *tsc);
return ret;
......
......@@ -129,7 +129,7 @@ static int nhm_start(void)
int num, cpu;
unsigned long long dbg, val;
nhm_get_count(TSC, &tsc_at_measure_start, 0);
nhm_get_count(TSC, &tsc_at_measure_start, base_cpu);
for (num = 0; num < NHM_CSTATE_COUNT; num++) {
for (cpu = 0; cpu < cpu_count; cpu++) {
......@@ -137,7 +137,7 @@ static int nhm_start(void)
previous_count[num][cpu] = val;
}
}
nhm_get_count(TSC, &dbg, 0);
nhm_get_count(TSC, &dbg, base_cpu);
dprint("TSC diff: %llu\n", dbg - tsc_at_measure_start);
return 0;
}
......@@ -148,7 +148,7 @@ static int nhm_stop(void)
unsigned long long dbg;
int num, cpu;
nhm_get_count(TSC, &tsc_at_measure_end, 0);
nhm_get_count(TSC, &tsc_at_measure_end, base_cpu);
for (num = 0; num < NHM_CSTATE_COUNT; num++) {
for (cpu = 0; cpu < cpu_count; cpu++) {
......@@ -156,7 +156,7 @@ static int nhm_stop(void)
current_count[num][cpu] = val;
}
}
nhm_get_count(TSC, &dbg, 0);
nhm_get_count(TSC, &dbg, base_cpu);
dprint("TSC diff: %llu\n", dbg - tsc_at_measure_end);
return 0;
......
......@@ -120,7 +120,7 @@ static int snb_start(void)
previous_count[num][cpu] = val;
}
}
snb_get_count(TSC, &tsc_at_measure_start, 0);
snb_get_count(TSC, &tsc_at_measure_start, base_cpu);
return 0;
}
......@@ -129,7 +129,7 @@ static int snb_stop(void)
unsigned long long val;
int num, cpu;
snb_get_count(TSC, &tsc_at_measure_end, 0);
snb_get_count(TSC, &tsc_at_measure_end, base_cpu);
for (num = 0; num < SNB_CSTATE_COUNT; num++) {
for (cpu = 0; cpu < cpu_count; cpu++) {
......
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