tools/power/turbostat: Read energy_perf_bias from sysfs

... instead of poking at the MSR directly.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-pm@vger.kernel.org
Link: https://lkml.kernel.org/r/20201029190259.3476-3-bp@alien8.de

diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 33b370865d16da6f2d6c966183d39a6cecbeed8d..0baec7ea1bbdd26ced30b118166ea0ad7118ecd3 100644 (file)
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -1721,6 +1721,25 @@ int get_mp(int cpu, struct msr_counter *mp, unsigned long long *counterp)
        return 0;
 }
 
+int get_epb(int cpu)
+{
+       char path[128 + PATH_BYTES];
+       int ret, epb = -1;
+       FILE *fp;
+
+       sprintf(path, "/sys/devices/system/cpu/cpu%d/power/energy_perf_bias", cpu);
+
+       fp = fopen_or_die(path, "r");
+
+       ret = fscanf(fp, "%d", &epb);
+       if (ret != 1)
+               err(1, "%s(%s)", __func__, path);
+
+       fclose(fp);
+
+       return epb;
+}
+
 void get_apic_id(struct thread_data *t)
 {
        unsigned int eax, ebx, ecx, edx;
@@ -3631,9 +3650,8 @@ dump_sysfs_pstate_config(void)
  */
 int print_epb(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 {
-       unsigned long long msr;
        char *epb_string;
-       int cpu;
+       int cpu, epb;
 
        if (!has_epb)
                return 0;
@@ -3649,10 +3667,11 @@ int print_epb(struct thread_data *t, struct core_data *c, struct pkg_data *p)
                return -1;
        }
 
-       if (get_msr(cpu, MSR_IA32_ENERGY_PERF_BIAS, &msr))
+       epb = get_epb(cpu);
+       if (epb < 0)
                return 0;
 
-       switch (msr & 0xF) {
+       switch (epb) {
        case ENERGY_PERF_BIAS_PERFORMANCE:
                epb_string = "performance";
                break;
@@ -3666,7 +3685,7 @@ int print_epb(struct thread_data *t, struct core_data *c, struct pkg_data *p)
                epb_string = "custom";
                break;
        }
-       fprintf(outf, "cpu%d: MSR_IA32_ENERGY_PERF_BIAS: 0x%08llx (%s)\n", cpu, msr, epb_string);
+       fprintf(outf, "cpu%d: EPB: %d (%s)\n", cpu, epb, epb_string);
 
        return 0;
 }