tools/power turbostat: relax dependency on invariant TSC

Turbostat can be useful on systems that do not support invariant TSC,
so allow it to run on those systgems.

All arithmetic in turbostat using the TSC value is per-processsor,
so it does not depend on the TSC values being in sync acrosss processors.

Turbostat uses gettimeofday() for the measurement interval
rather than using the TSC directly, so that key metric
is also immune from variable TSC.

Turbostat prints a TSC sanity check column:

TSC_MHz = TSC_delta/interval

If this column is constant and is close to the processor
base frequency, then the TSC is behaving properly.

The other key turbostat columns are calculated this way:

Avg_Mhz = APERF_delta/interval

%Busy = MPERF_delta/TSC_delta

Bzy_MHz = TSC_delta/APERF_delta/MPERF_delta/interval

Tested on Core2 and Core2-Xeon, and so this patch includes
a few other changes to remove the assumption that target
systems are Nehalem and newer.
Signed-off-by: Len Brown <len.brown@intel.com>

tools/power/x86/turbostat/turbostat.c

@@ -61,8 +61,8 @@ unsigned int has_epb;
 unsigned int units = 1000000;	/* MHz etc */
 unsigned int genuine_intel;
 unsigned int has_invariant_tsc;
-unsigned int do_nehalem_platform_info;
-unsigned int do_nehalem_turbo_ratio_limit;
+unsigned int do_nhm_platform_info;
+unsigned int do_nhm_turbo_ratio_limit;
 unsigned int do_ivt_turbo_ratio_limit;
 unsigned int extra_msr_offset32;
 unsigned int extra_msr_offset64;
@@ -284,7 +284,7 @@ void print_header(void)
 		outp += sprintf(outp, "     CPU");
 	if (has_aperf)
 		outp += sprintf(outp, " Avg_MHz");
-	if (do_nhm_cstates)
+	if (has_aperf)
 		outp += sprintf(outp, "   %%Busy");
 	if (has_aperf)
 		outp += sprintf(outp, " Bzy_MHz");
@@ -340,7 +340,7 @@ void print_header(void)
 			outp += sprintf(outp, "   PKG_%%");
 		if (do_rapl & RAPL_DRAM_PERF_STATUS)
 			outp += sprintf(outp, "   RAM_%%");
-	} else {
+	} else if (do_rapl && rapl_joules) {
 		if (do_rapl & RAPL_PKG)
 			outp += sprintf(outp, "   Pkg_J");
 		if (do_rapl & RAPL_CORES)
@@ -460,25 +460,25 @@ int format_counters(struct thread_data *t, struct core_data *c,
 			outp += sprintf(outp, "%8d", t->cpu_id);
 	}
 
-	/* AvgMHz */
+	/* Avg_MHz */
 	if (has_aperf)
 		outp += sprintf(outp, "%8.0f",
 			1.0 / units * t->aperf / interval_float);
 
-	/* %c0 */
-	if (do_nhm_cstates) {
+	/* %Busy */
+	if (has_aperf) {
 		if (!skip_c0)
 			outp += sprintf(outp, "%8.2f", 100.0 * t->mperf/t->tsc);
 		else
 			outp += sprintf(outp, "********");
 	}
 
-	/* BzyMHz */
+	/* Bzy_MHz */
 	if (has_aperf)
 		outp += sprintf(outp, "%8.0f",
 			1.0 * t->tsc / units * t->aperf / t->mperf / interval_float);
 
-	/* TSC */
+	/* TSC_MHz */
 	outp += sprintf(outp, "%8.0f", 1.0 * t->tsc/units/interval_float);
 
 	/* SMI */
@@ -564,7 +564,7 @@ int format_counters(struct thread_data *t, struct core_data *c,
 			outp += sprintf(outp, fmt8, 100.0 * p->rapl_pkg_perf_status * rapl_time_units / interval_float);
 		if (do_rapl & RAPL_DRAM_PERF_STATUS)
 			outp += sprintf(outp, fmt8, 100.0 * p->rapl_dram_perf_status * rapl_time_units / interval_float);
-	} else {
+	} else if (do_rapl && rapl_joules) {
 		if (do_rapl & RAPL_PKG)
 			outp += sprintf(outp, fmt8,
 					p->energy_pkg * rapl_energy_units);
@@ -581,8 +581,8 @@ int format_counters(struct thread_data *t, struct core_data *c,
 			outp += sprintf(outp, fmt8, 100.0 * p->rapl_pkg_perf_status * rapl_time_units / interval_float);
 		if (do_rapl & RAPL_DRAM_PERF_STATUS)
 			outp += sprintf(outp, fmt8, 100.0 * p->rapl_dram_perf_status * rapl_time_units / interval_float);
-	outp += sprintf(outp, fmt8, interval_float);
 
+		outp += sprintf(outp, fmt8, interval_float);
 	}
 done:
 	outp += sprintf(outp, "\n");
@@ -1022,7 +1022,7 @@ void print_verbose_header(void)
 	unsigned long long msr;
 	unsigned int ratio;
 
-	if (!do_nehalem_platform_info)
+	if (!do_nhm_platform_info)
 		return;
 
 	get_msr(0, MSR_NHM_PLATFORM_INFO, &msr);
@@ -1135,7 +1135,7 @@ void print_verbose_header(void)
 	}
 	fprintf(stderr, ")\n");
 
-	if (!do_nehalem_turbo_ratio_limit)
+	if (!do_nhm_turbo_ratio_limit)
 		return;
 
 	get_msr(0, MSR_NHM_TURBO_RATIO_LIMIT, &msr);
@@ -1462,8 +1462,7 @@ void check_dev_msr()
 	struct stat sb;
 
 	if (stat("/dev/cpu/0/msr", &sb))
-		err(-5, "no /dev/cpu/0/msr\n"
-		    "Try \"# modprobe msr\"");
+		err(-5, "no /dev/cpu/0/msr, Try \"# modprobe msr\" ");
 }
 
 void check_permissions()
@@ -1496,13 +1495,27 @@ void check_permissions()
 	/* if all else fails, thell them to be root */
 	if (do_exit)
 		if (getuid() != 0)
-			warnx("Or simply run as root");
+			warnx("... or simply run as root");
 
 	if (do_exit)
 		exit(-6);
 }
 
-int has_nehalem_turbo_ratio_limit(unsigned int family, unsigned int model)
+/*
+ * NHM adds support for additional MSRs:
+ *
+ * MSR_SMI_COUNT                   0x00000034
+ *
+ * MSR_NHM_PLATFORM_INFO           0x000000ce
+ * MSR_NHM_SNB_PKG_CST_CFG_CTL     0x000000e2
+ *
+ * MSR_PKG_C3_RESIDENCY            0x000003f8
+ * MSR_PKG_C6_RESIDENCY            0x000003f9
+ * MSR_CORE_C3_RESIDENCY           0x000003fc
+ * MSR_CORE_C6_RESIDENCY           0x000003fd
+ *
+ */
+int has_nhm_msrs(unsigned int family, unsigned int model)
 {
 	if (!genuine_intel)
 		return 0;
@@ -1529,13 +1542,27 @@ int has_nehalem_turbo_ratio_limit(unsigned int family, unsigned int model)
 	case 0x3D:	/* BDW */
 	case 0x4F:	/* BDX */
 	case 0x56:	/* BDX-DE */
-		return 1;
 	case 0x2E:	/* Nehalem-EX Xeon - Beckton */
 	case 0x2F:	/* Westmere-EX Xeon - Eagleton */
+		return 1;
 	default:
 		return 0;
 	}
 }
+int has_nhm_turbo_ratio_limit(unsigned int family, unsigned int model)
+{
+	if (!has_nhm_msrs(family, model))
+		return 0;
+
+	switch (model) {
+	/* Nehalem compatible, but do not include turbo-ratio limit support */
+	case 0x2E:	/* Nehalem-EX Xeon - Beckton */
+	case 0x2F:	/* Westmere-EX Xeon - Eagleton */
+		return 0;
+	default:
+		return 1;
+	}
+}
 int has_ivt_turbo_ratio_limit(unsigned int family, unsigned int model)
 {
 	if (!genuine_intel)
@@ -1994,8 +2021,15 @@ int print_rapl(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 	return 0;
 }
 
+/*
+ * SNB adds support for additional MSRs:
+ *
+ * MSR_PKG_C7_RESIDENCY            0x000003fa
+ * MSR_CORE_C7_RESIDENCY           0x000003fe
+ * MSR_PKG_C2_RESIDENCY            0x0000060d
+ */
 
-int is_snb(unsigned int family, unsigned int model)
+int has_snb_msrs(unsigned int family, unsigned int model)
 {
 	if (!genuine_intel)
 		return 0;
@@ -2017,7 +2051,14 @@ int is_snb(unsigned int family, unsigned int model)
 	return 0;
 }
 
-int has_c8_c9_c10(unsigned int family, unsigned int model)
+/*
+ * HSW adds support for additional MSRs:
+ *
+ * MSR_PKG_C8_RESIDENCY            0x00000630
+ * MSR_PKG_C9_RESIDENCY            0x00000631
+ * MSR_PKG_C10_RESIDENCY           0x00000632
+ */
+int has_hsw_msrs(unsigned int family, unsigned int model)
 {
 	if (!genuine_intel)
 		return 0;
@@ -2069,7 +2110,7 @@ double slm_bclk(void)
 
 double discover_bclk(unsigned int family, unsigned int model)
 {
-	if (is_snb(family, model))
+	if (has_snb_msrs(family, model))
 		return 100.00;
 	else if (is_slm(family, model))
 		return slm_bclk();
@@ -2117,7 +2158,7 @@ int set_temperature_target(struct thread_data *t, struct core_data *c, struct pk
 	}
 
 	/* Temperature Target MSR is Nehalem and newer only */
-	if (!do_nehalem_platform_info)
+	if (!do_nhm_platform_info)
 		goto guess;
 
 	if (get_msr(0, MSR_IA32_TEMPERATURE_TARGET, &msr))
@@ -2181,8 +2222,7 @@ void check_cpuid()
 	ebx = ecx = edx = 0;
 	__get_cpuid(0x80000000, &max_level, &ebx, &ecx, &edx);
 
-	if (max_level < 0x80000007)
-		errx(1, "CPUID: no invariant TSC (max_level 0x%x)", max_level);
+	if (max_level >= 0x80000007) {
 
 		/*
 		 * Non-Stop TSC is advertised by CPUID.EAX=0x80000007: EDX.bit8
@@ -2190,9 +2230,7 @@ void check_cpuid()
 		 */
 		__get_cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
 		has_invariant_tsc = edx & (1 << 8);
-
-	if (!has_invariant_tsc)
-		errx(1, "No invariant TSC");
+	}
 
 	/*
 	 * APERF/MPERF is advertised by CPUID.EAX=0x6: ECX.bit0
@@ -2215,15 +2253,13 @@ void check_cpuid()
 	if (!has_aperf)
 		errx(-1, "No APERF");
 
-	do_nehalem_platform_info = genuine_intel && has_invariant_tsc;
-	do_nhm_cstates = genuine_intel;	/* all Intel w/ non-stop TSC have NHM counters */
-	do_smi = do_nhm_cstates;
-	do_snb_cstates = is_snb(family, model);
-	do_c8_c9_c10 = has_c8_c9_c10(family, model);
+	do_nhm_platform_info = do_nhm_cstates = do_smi = has_nhm_msrs(family, model);
+	do_snb_cstates = has_snb_msrs(family, model);
+	do_c8_c9_c10 = has_hsw_msrs(family, model);
 	do_slm_cstates = is_slm(family, model);
 	bclk = discover_bclk(family, model);
 
-	do_nehalem_turbo_ratio_limit = has_nehalem_turbo_ratio_limit(family, model);
+	do_nhm_turbo_ratio_limit = has_nhm_turbo_ratio_limit(family, model);
 	do_ivt_turbo_ratio_limit = has_ivt_turbo_ratio_limit(family, model);
 	rapl_probe(family, model);
 	perf_limit_reasons_probe(family, model);