Linux-libre 4.6.2-gnu

2 files changed, 825 insertions, 201 deletions

diff --git a/tools/power/x86/turbostat/turbostat.8 b/tools/power/x86/turbostat/turbostat.8
index 622db685b..89a55d5e3 100644
--- a/tools/power/x86/turbostat/turbostat.8
+++ b/tools/power/x86/turbostat/turbostat.8
@@ -34,7 +34,10 @@ name as necessary to disambiguate it from others is necessary.  Note that option
 \fB--debug\fP displays additional system configuration information.  Invoking this parameter
 more than once may also enable internal turbostat debug information.
 .PP
-\fB--interval seconds\fP overrides the default 5-second measurement interval.
+\fB--interval seconds\fP overrides the default 5.0 second measurement interval.
+.PP
+\fB--out output_file\fP turbostat output is written to the specified output_file.
+The file is truncated if it already exists, and it is created if it does not exist.
 .PP
 \fB--help\fP displays usage for the most common parameters.
 .PP
@@ -61,7 +64,7 @@ displays the statistics gathered since it was forked.
 .nf
 \fBCPU\fP Linux CPU (logical processor) number.  Yes, it is okay that on many systems the CPUs are not listed in numerical order -- for efficiency reasons, turbostat runs in topology order, so HT siblings appear together.
 \fBAVG_MHz\fP number of cycles executed divided by time elapsed.
-\fB%Busy\fP percent of the interval that the CPU retired instructions, aka. % of time in "C0" state.
+\fBBusy%\fP percent of the interval that the CPU retired instructions, aka. % of time in "C0" state.
 \fBBzy_MHz\fP average clock rate while the CPU was busy (in "c0" state).
 \fBTSC_MHz\fP average MHz that the TSC ran during the entire interval.
 .fi
@@ -83,13 +86,14 @@ Note that multiple CPUs per core indicate support for Intel(R) Hyper-Threading T
 \fBRAM_%\fP percent of the interval that RAPL throttling was active on DRAM.
 .fi
 .PP
-.SH EXAMPLE
+.SH PERIODIC EXAMPLE
 Without any parameters, turbostat displays statistics ever 5 seconds.
-(override interval with "-i sec" option, or specify a command
-for turbostat to fork).
+Periodic output goes to stdout, by default, unless --out is used to specify an output file.
+The 5-second interval can be changed with th "-i sec" option.
+Or a command may be specified as in "FORK EXAMPLE" below.
 .nf
 [root@hsw]# ./turbostat
-     CPU Avg_MHz   %Busy Bzy_MHz TSC_MHz
+     CPU Avg_MHz   Busy% Bzy_MHz TSC_MHz
        -     488   12.51    3898    3498
        0       0    0.01    3885    3498
        4    3897   99.99    3898    3498
@@ -145,7 +149,7 @@ cpu0: MSR_IA32_THERM_STATUS: 0x88340000 (48 C +/- 1)
 cpu1: MSR_IA32_THERM_STATUS: 0x88440000 (32 C +/- 1)
 cpu2: MSR_IA32_THERM_STATUS: 0x88450000 (31 C +/- 1)
 cpu3: MSR_IA32_THERM_STATUS: 0x88490000 (27 C +/- 1)
-    Core     CPU Avg_MHz   %Busy Bzy_MHz TSC_MHz     SMI  CPU%c1  CPU%c3  CPU%c6  CPU%c7 CoreTmp  PkgTmp PkgWatt CorWatt GFXWatt
+    Core     CPU Avg_MHz   Busy% Bzy_MHz TSC_MHz     SMI  CPU%c1  CPU%c3  CPU%c6  CPU%c7 CoreTmp  PkgTmp PkgWatt CorWatt GFXWatt
        -       -     493   12.64    3898    3498       0   12.64    0.00    0.00   74.72      47      47   21.62   13.74    0.00
        0       0       4    0.11    3894    3498       0   99.89    0.00    0.00    0.00      47      47   21.62   13.74    0.00
        0       4    3897   99.98    3898    3498       0    0.02
@@ -171,14 +175,16 @@ The --debug option adds additional columns to the measurement ouput, including C
 See the field definitions above.
 .SH FORK EXAMPLE
 If turbostat is invoked with a command, it will fork that command
-and output the statistics gathered when the command exits.
+and output the statistics gathered after the command exits.
+In this case, turbostat output goes to stderr, by default.
+Output can instead be saved to a file using the --out option.
 eg. Here a cycle soaker is run on 1 CPU (see %c0) for a few seconds
 until ^C while the other CPUs are mostly idle:
 
 .nf
 root@hsw: turbostat cat /dev/zero > /dev/null
 ^C
-     CPU Avg_MHz   %Busy Bzy_MHz TSC_MHz
+     CPU Avg_MHz   Busy% Bzy_MHz TSC_MHz
        -     482   12.51    3854    3498
        0       0    0.01    1960    3498
        4       0    0.00    2128    3498
@@ -192,12 +198,12 @@ root@hsw: turbostat cat /dev/zero > /dev/null
 
 .fi
 Above the cycle soaker drives cpu5 up its 3.9 GHz turbo limit.
-The first row shows the average MHz and %Busy across all the processors in the system.
+The first row shows the average MHz and Busy% across all the processors in the system.
 
 Note that the Avg_MHz column reflects the total number of cycles executed
-divided by the measurement interval.  If the %Busy column is 100%,
+divided by the measurement interval.  If the Busy% column is 100%,
 then the processor was running at that speed the entire interval.
-The Avg_MHz multiplied by the %Busy results in the Bzy_MHz --
+The Avg_MHz multiplied by the Busy% results in the Bzy_MHz --
 which is the average frequency while the processor was executing --
 not including any non-busy idle time.
 
@@ -233,7 +239,7 @@ in the brand string in /proc/cpuinfo.  On a system where
 the TSC stops in idle, TSC_MHz will drop
 below the processor's base frequency.
 
-%Busy = MPERF_delta/TSC_delta
+Busy% = MPERF_delta/TSC_delta
 
 Bzy_MHz = TSC_delta/APERF_delta/MPERF_delta/measurement_interval
 
diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 0dac7e05a..acbf7ff2e 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -38,12 +38,15 @@
 #include <string.h>
 #include <ctype.h>
 #include <sched.h>
+#include <time.h>
 #include <cpuid.h>
 #include <linux/capability.h>
 #include <errno.h>
 
 char *proc_stat = "/proc/stat";
-unsigned int interval_sec = 5;
+FILE *outf;
+int *fd_percpu;
+struct timespec interval_ts = {5, 0};
 unsigned int debug;
 unsigned int rapl_joules;
 unsigned int summary_only;
@@ -63,6 +66,8 @@ unsigned int do_slm_cstates;
 unsigned int use_c1_residency_msr;
 unsigned int has_aperf;
 unsigned int has_epb;
+unsigned int do_irtl_snb;
+unsigned int do_irtl_hsw;
 unsigned int units = 1000000;	/* MHz etc */
 unsigned int genuine_intel;
 unsigned int has_invariant_tsc;
@@ -72,6 +77,7 @@ unsigned int extra_msr_offset64;
 unsigned int extra_delta_offset32;
 unsigned int extra_delta_offset64;
 unsigned int aperf_mperf_multiplier = 1;
+int do_irq = 1;
 int do_smi;
 double bclk;
 double base_hz;
@@ -86,6 +92,10 @@ char *output_buffer, *outp;
 unsigned int do_rapl;
 unsigned int do_dts;
 unsigned int do_ptm;
+unsigned int do_gfx_rc6_ms;
+unsigned long long  gfx_cur_rc6_ms;
+unsigned int do_gfx_mhz;
+unsigned int gfx_cur_mhz;
 unsigned int tcc_activation_temp;
 unsigned int tcc_activation_temp_override;
 double rapl_power_units, rapl_time_units;
@@ -98,6 +108,12 @@ unsigned int crystal_hz;
 unsigned long long tsc_hz;
 int base_cpu;
 double discover_bclk(unsigned int family, unsigned int model);
+unsigned int has_hwp;	/* IA32_PM_ENABLE, IA32_HWP_CAPABILITIES */
+			/* IA32_HWP_REQUEST, IA32_HWP_STATUS */
+unsigned int has_hwp_notify;		/* IA32_HWP_INTERRUPT */
+unsigned int has_hwp_activity_window;	/* IA32_HWP_REQUEST[bits 41:32] */
+unsigned int has_hwp_epp;		/* IA32_HWP_REQUEST[bits 31:24] */
+unsigned int has_hwp_pkg;		/* IA32_HWP_REQUEST_PKG */
 
 #define RAPL_PKG		(1 << 0)
 					/* 0x610 MSR_PKG_POWER_LIMIT */
@@ -145,6 +161,7 @@ struct thread_data {
 	unsigned long long extra_delta64;
 	unsigned long long extra_msr32;
 	unsigned long long extra_delta32;
+	unsigned int irq_count;
 	unsigned int smi_count;
 	unsigned int cpu_id;
 	unsigned int flags;
@@ -172,6 +189,8 @@ struct pkg_data {
 	unsigned long long pkg_any_core_c0;
 	unsigned long long pkg_any_gfxe_c0;
 	unsigned long long pkg_both_core_gfxe_c0;
+	long long gfx_rc6_ms;
+	unsigned int gfx_mhz;
 	unsigned int package_id;
 	unsigned int energy_pkg;	/* MSR_PKG_ENERGY_STATUS */
 	unsigned int energy_dram;	/* MSR_DRAM_ENERGY_STATUS */
@@ -212,6 +231,9 @@ struct topo_params {
 
 struct timeval tv_even, tv_odd, tv_delta;
 
+int *irq_column_2_cpu;	/* /proc/interrupts column numbers */
+int *irqs_per_cpu;		/* indexed by cpu_num */
+
 void setup_all_buffers(void);
 
 int cpu_is_not_present(int cpu)
@@ -262,23 +284,34 @@ int cpu_migrate(int cpu)
 	else
 		return 0;
 }
-
-int get_msr(int cpu, off_t offset, unsigned long long *msr)
+int get_msr_fd(int cpu)
 {
-	ssize_t retval;
 	char pathname[32];
 	int fd;
 
+	fd = fd_percpu[cpu];
+
+	if (fd)
+		return fd;
+
 	sprintf(pathname, "/dev/cpu/%d/msr", cpu);
 	fd = open(pathname, O_RDONLY);
 	if (fd < 0)
 		err(-1, "%s open failed, try chown or chmod +r /dev/cpu/*/msr, or run as root", pathname);
 
-	retval = pread(fd, msr, sizeof *msr, offset);
-	close(fd);
+	fd_percpu[cpu] = fd;
+
+	return fd;
+}
+
+int get_msr(int cpu, off_t offset, unsigned long long *msr)
+{
+	ssize_t retval;
+
+	retval = pread(get_msr_fd(cpu), msr, sizeof(*msr), offset);
 
 	if (retval != sizeof *msr)
-		err(-1, "%s offset 0x%llx read failed", pathname, (unsigned long long)offset);
+		err(-1, "msr %d offset 0x%llx read failed", cpu, (unsigned long long)offset);
 
 	return 0;
 }
@@ -286,8 +319,8 @@ int get_msr(int cpu, off_t offset, unsigned long long *msr)
 /*
  * Example Format w/ field column widths:
  *
- *  Package    Core     CPU Avg_MHz Bzy_MHz TSC_MHz     SMI   %Busy CPU_%c1 CPU_%c3 CPU_%c6 CPU_%c7 CoreTmp  PkgTmp Pkg%pc2 Pkg%pc3 Pkg%pc6 Pkg%pc7 PkgWatt CorWatt GFXWatt
- * 123456781234567812345678123456781234567812345678123456781234567812345678123456781234567812345678123456781234567812345678123456781234567812345678123456781234567812345678
+ *  Package    Core     CPU Avg_MHz Bzy_MHz TSC_MHz     IRQ   SMI   Busy% CPU_%c1 CPU_%c3 CPU_%c6 CPU_%c7 CoreTmp  PkgTmp  GFXMHz Pkg%pc2 Pkg%pc3 Pkg%pc6 Pkg%pc7 PkgWatt CorWatt GFXWatt
+ * 12345678123456781234567812345678123456781234567812345678123456781234567812345678123456781234567812345678123456781234567812345678123456781234567812345678123456781234567812345678
  */
 
 void print_header(void)
@@ -301,7 +334,7 @@ void print_header(void)
 	if (has_aperf)
 		outp += sprintf(outp, " Avg_MHz");
 	if (has_aperf)
-		outp += sprintf(outp, "   %%Busy");
+		outp += sprintf(outp, "   Busy%%");
 	if (has_aperf)
 		outp += sprintf(outp, " Bzy_MHz");
 	outp += sprintf(outp, " TSC_MHz");
@@ -318,6 +351,8 @@ void print_header(void)
 	if (!debug)
 		goto done;
 
+	if (do_irq)
+		outp += sprintf(outp, "     IRQ");
 	if (do_smi)
 		outp += sprintf(outp, "     SMI");
 
@@ -335,6 +370,12 @@ void print_header(void)
 	if (do_ptm)
 		outp += sprintf(outp, "  PkgTmp");
 
+	if (do_gfx_rc6_ms)
+		outp += sprintf(outp, " GFX%%rc6");
+
+	if (do_gfx_mhz)
+		outp += sprintf(outp, "  GFXMHz");
+
 	if (do_skl_residency) {
 		outp += sprintf(outp, " Totl%%C0");
 		outp += sprintf(outp, "  Any%%C0");
@@ -409,6 +450,8 @@ int dump_counters(struct thread_data *t, struct core_data *c,
 			extra_msr_offset32, t->extra_msr32);
 		outp += sprintf(outp, "msr0x%x: %016llX\n",
 			extra_msr_offset64, t->extra_msr64);
+		if (do_irq)
+			outp += sprintf(outp, "IRQ: %08X\n", t->irq_count);
 		if (do_smi)
 			outp += sprintf(outp, "SMI: %08X\n", t->smi_count);
 	}
@@ -504,7 +547,7 @@ int format_counters(struct thread_data *t, struct core_data *c,
 		outp += sprintf(outp, "%8.0f",
 			1.0 / units * t->aperf / interval_float);
 
-	/* %Busy */
+	/* Busy% */
 	if (has_aperf) {
 		if (!skip_c0)
 			outp += sprintf(outp, "%8.2f", 100.0 * t->mperf/t->tsc/tsc_tweak);
@@ -542,6 +585,10 @@ int format_counters(struct thread_data *t, struct core_data *c,
 	if (!debug)
 		goto done;
 
+	/* IRQ */
+	if (do_irq)
+		outp += sprintf(outp, "%8d", t->irq_count);
+
 	/* SMI */
 	if (do_smi)
 		outp += sprintf(outp, "%8d", t->smi_count);
@@ -575,6 +622,20 @@ int format_counters(struct thread_data *t, struct core_data *c,
 	if (do_ptm)
 		outp += sprintf(outp, "%8d", p->pkg_temp_c);
 
+	/* GFXrc6 */
+	if (do_gfx_rc6_ms) {
+		if (p->gfx_rc6_ms == -1) {	/* detect counter reset */
+			outp += sprintf(outp, "  ***.**");
+		} else {
+			outp += sprintf(outp, "%8.2f",
+				p->gfx_rc6_ms / 10.0 / interval_float);
+		}
+	}
+
+	/* GFXMHz */
+	if (do_gfx_mhz)
+		outp += sprintf(outp, "%8d", p->gfx_mhz);
+
 	/* Totl%C0, Any%C0 GFX%C0 CPUGFX% */
 	if (do_skl_residency) {
 		outp += sprintf(outp, "%8.2f", 100.0 * p->pkg_wtd_core_c0/t->tsc);
@@ -645,15 +706,24 @@ done:
 	return 0;
 }
 
-void flush_stdout()
+void flush_output_stdout(void)
 {
-	fputs(output_buffer, stdout);
-	fflush(stdout);
+	FILE *filep;
+
+	if (outf == stderr)
+		filep = stdout;
+	else
+		filep = outf;
+
+	fputs(output_buffer, filep);
+	fflush(filep);
+
 	outp = output_buffer;
 }
-void flush_stderr()
+void flush_output_stderr(void)
 {
-	fputs(output_buffer, stderr);
+	fputs(output_buffer, outf);
+	fflush(outf);
 	outp = output_buffer;
 }
 void format_all_counters(struct thread_data *t, struct core_data *c, struct pkg_data *p)
@@ -704,6 +774,14 @@ delta_package(struct pkg_data *new, struct pkg_data *old)
 	old->pc10 = new->pc10 - old->pc10;
 	old->pkg_temp_c = new->pkg_temp_c;
 
+	/* flag an error when rc6 counter resets/wraps */
+	if (old->gfx_rc6_ms >  new->gfx_rc6_ms)
+		old->gfx_rc6_ms = -1;
+	else
+		old->gfx_rc6_ms = new->gfx_rc6_ms - old->gfx_rc6_ms;
+
+	old->gfx_mhz = new->gfx_mhz;
+
 	DELTA_WRAP32(new->energy_pkg, old->energy_pkg);
 	DELTA_WRAP32(new->energy_cores, old->energy_cores);
 	DELTA_WRAP32(new->energy_gfx, old->energy_gfx);
@@ -745,9 +823,9 @@ delta_thread(struct thread_data *new, struct thread_data *old,
 		} else {
 
 			if (!aperf_mperf_unstable) {
-				fprintf(stderr, "%s: APERF or MPERF went backwards *\n", progname);
-				fprintf(stderr, "* Frequency results do not cover entire interval *\n");
-				fprintf(stderr, "* fix this by running Linux-2.6.30 or later *\n");
+				fprintf(outf, "%s: APERF or MPERF went backwards *\n", progname);
+				fprintf(outf, "* Frequency results do not cover entire interval *\n");
+				fprintf(outf, "* fix this by running Linux-2.6.30 or later *\n");
 
 				aperf_mperf_unstable = 1;
 			}
@@ -782,7 +860,8 @@ delta_thread(struct thread_data *new, struct thread_data *old,
 	}
 
 	if (old->mperf == 0) {
-		if (debug > 1) fprintf(stderr, "cpu%d MPERF 0!\n", old->cpu_id);
+		if (debug > 1)
+			fprintf(outf, "cpu%d MPERF 0!\n", old->cpu_id);
 		old->mperf = 1;	/* divide by 0 protection */
 	}
 
@@ -797,6 +876,9 @@ delta_thread(struct thread_data *new, struct thread_data *old,
 	old->extra_msr32 = new->extra_msr32;
 	old->extra_msr64 = new->extra_msr64;
 
+	if (do_irq)
+		old->irq_count = new->irq_count - old->irq_count;
+
 	if (do_smi)
 		old->smi_count = new->smi_count - old->smi_count;
 }
@@ -826,10 +908,12 @@ void clear_counters(struct thread_data *t, struct core_data *c, struct pkg_data
 	t->mperf = 0;
 	t->c1 = 0;
 
-	t->smi_count = 0;
 	t->extra_delta32 = 0;
 	t->extra_delta64 = 0;
 
+	t->irq_count = 0;
+	t->smi_count = 0;
+
 	/* tells format_counters to dump all fields from this set */
 	t->flags = CPU_IS_FIRST_THREAD_IN_CORE | CPU_IS_FIRST_CORE_IN_PACKAGE;
 
@@ -861,6 +945,9 @@ void clear_counters(struct thread_data *t, struct core_data *c, struct pkg_data
 	p->rapl_pkg_perf_status = 0;
 	p->rapl_dram_perf_status = 0;
 	p->pkg_temp_c = 0;
+
+	p->gfx_rc6_ms = 0;
+	p->gfx_mhz = 0;
 }
 int sum_counters(struct thread_data *t, struct core_data *c,
 	struct pkg_data *p)
@@ -873,6 +960,9 @@ int sum_counters(struct thread_data *t, struct core_data *c,
 	average.threads.extra_delta32 += t->extra_delta32;
 	average.threads.extra_delta64 += t->extra_delta64;
 
+	average.threads.irq_count += t->irq_count;
+	average.threads.smi_count += t->smi_count;
+
 	/* sum per-core values only for 1st thread in core */
 	if (!(t->flags & CPU_IS_FIRST_THREAD_IN_CORE))
 		return 0;
@@ -910,6 +1000,9 @@ int sum_counters(struct thread_data *t, struct core_data *c,
 	average.packages.energy_cores += p->energy_cores;
 	average.packages.energy_gfx += p->energy_gfx;
 
+	average.packages.gfx_rc6_ms = p->gfx_rc6_ms;
+	average.packages.gfx_mhz = p->gfx_mhz;
+
 	average.packages.pkg_temp_c = MAX(average.packages.pkg_temp_c, p->pkg_temp_c);
 
 	average.packages.rapl_pkg_perf_status += p->rapl_pkg_perf_status;
@@ -970,7 +1063,6 @@ static unsigned long long rdtsc(void)
 	return low | ((unsigned long long)high) << 32;
 }
 
-
 /*
  * get_counters(...)
  * migrate to cpu
@@ -980,23 +1072,74 @@ int get_counters(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 {
 	int cpu = t->cpu_id;
 	unsigned long long msr;
+	int aperf_mperf_retry_count = 0;
 
 	if (cpu_migrate(cpu)) {
-		fprintf(stderr, "Could not migrate to CPU %d\n", cpu);
+		fprintf(outf, "Could not migrate to CPU %d\n", cpu);
 		return -1;
 	}
 
+retry:
 	t->tsc = rdtsc();	/* we are running on local CPU of interest */
 
 	if (has_aperf) {
+		unsigned long long tsc_before, tsc_between, tsc_after, aperf_time, mperf_time;
+
+		/*
+		 * The TSC, APERF and MPERF must be read together for
+		 * APERF/MPERF and MPERF/TSC to give accurate results.
+		 *
+		 * Unfortunately, APERF and MPERF are read by
+		 * individual system call, so delays may occur
+		 * between them.  If the time to read them
+		 * varies by a large amount, we re-read them.
+		 */
+
+		/*
+		 * This initial dummy APERF read has been seen to
+		 * reduce jitter in the subsequent reads.
+		 */
+
+		if (get_msr(cpu, MSR_IA32_APERF, &t->aperf))
+			return -3;
+
+		t->tsc = rdtsc();	/* re-read close to APERF */
+
+		tsc_before = t->tsc;
+
 		if (get_msr(cpu, MSR_IA32_APERF, &t->aperf))
 			return -3;
+
+		tsc_between = rdtsc();
+
 		if (get_msr(cpu, MSR_IA32_MPERF, &t->mperf))
 			return -4;
+
+		tsc_after = rdtsc();
+
+		aperf_time = tsc_between - tsc_before;
+		mperf_time = tsc_after - tsc_between;
+
+		/*
+		 * If the system call latency to read APERF and MPERF
+		 * differ by more than 2x, then try again.
+		 */
+		if ((aperf_time > (2 * mperf_time)) || (mperf_time > (2 * aperf_time))) {
+			aperf_mperf_retry_count++;
+			if (aperf_mperf_retry_count < 5)
+				goto retry;
+			else
+				warnx("cpu%d jitter %lld %lld",
+					cpu, aperf_time, mperf_time);
+		}
+		aperf_mperf_retry_count = 0;
+
 		t->aperf = t->aperf * aperf_mperf_multiplier;
 		t->mperf = t->mperf * aperf_mperf_multiplier;
 	}
 
+	if (do_irq)
+		t->irq_count = irqs_per_cpu[cpu];
 	if (do_smi) {
 		if (get_msr(cpu, MSR_SMI_COUNT, &msr))
 			return -5;
@@ -1124,6 +1267,13 @@ int get_counters(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 			return -17;
 		p->pkg_temp_c = tcc_activation_temp - ((msr >> 16) & 0x7F);
 	}
+
+	if (do_gfx_rc6_ms)
+		p->gfx_rc6_ms = gfx_cur_rc6_ms;
+
+	if (do_gfx_mhz)
+		p->gfx_mhz = gfx_cur_mhz;
+
 	return 0;
 }
 
@@ -1159,6 +1309,7 @@ int hsw_pkg_cstate_limits[16] = {PCL__0, PCL__2, PCL__3, PCL__6, PCL__7, PCL_7S,
 int slv_pkg_cstate_limits[16] = {PCL__0, PCL__1, PCLRSV, PCLRSV, PCL__4, PCLRSV, PCL__6, PCL__7, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV};
 int amt_pkg_cstate_limits[16] = {PCL__0, PCL__1, PCL__2, PCLRSV, PCLRSV, PCLRSV, PCL__6, PCL__7, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV};
 int phi_pkg_cstate_limits[16] = {PCL__0, PCL__2, PCL_6N, PCL_6R, PCLRSV, PCLRSV, PCLRSV, PCLUNL, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV};
+int bxt_pkg_cstate_limits[16] = {PCL__0, PCL__2, PCLUNL, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV, PCLRSV};
 
 
 static void
@@ -1175,18 +1326,18 @@ dump_nhm_platform_info(void)
 
 	get_msr(base_cpu, MSR_PLATFORM_INFO, &msr);
 
-	fprintf(stderr, "cpu%d: MSR_PLATFORM_INFO: 0x%08llx\n", base_cpu, msr);
+	fprintf(outf, "cpu%d: MSR_PLATFORM_INFO: 0x%08llx\n", base_cpu, msr);
 
 	ratio = (msr >> 40) & 0xFF;
-	fprintf(stderr, "%d * %.0f = %.0f MHz max efficiency frequency\n",
+	fprintf(outf, "%d * %.0f = %.0f MHz max efficiency frequency\n",
 		ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 8) & 0xFF;
-	fprintf(stderr, "%d * %.0f = %.0f MHz base frequency\n",
+	fprintf(outf, "%d * %.0f = %.0f MHz base frequency\n",
 		ratio, bclk, ratio * bclk);
 
 	get_msr(base_cpu, MSR_IA32_POWER_CTL, &msr);
-	fprintf(stderr, "cpu%d: MSR_IA32_POWER_CTL: 0x%08llx (C1E auto-promotion: %sabled)\n",
+	fprintf(outf, "cpu%d: MSR_IA32_POWER_CTL: 0x%08llx (C1E auto-promotion: %sabled)\n",
 		base_cpu, msr, msr & 0x2 ? "EN" : "DIS");
 
 	return;
@@ -1200,16 +1351,16 @@ dump_hsw_turbo_ratio_limits(void)
 
 	get_msr(base_cpu, MSR_TURBO_RATIO_LIMIT2, &msr);
 
-	fprintf(stderr, "cpu%d: MSR_TURBO_RATIO_LIMIT2: 0x%08llx\n", base_cpu, msr);
+	fprintf(outf, "cpu%d: MSR_TURBO_RATIO_LIMIT2: 0x%08llx\n", base_cpu, msr);
 
 	ratio = (msr >> 8) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 18 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 18 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 0) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 17 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 17 active cores\n",
 			ratio, bclk, ratio * bclk);
 	return;
 }
@@ -1222,46 +1373,46 @@ dump_ivt_turbo_ratio_limits(void)
 
 	get_msr(base_cpu, MSR_TURBO_RATIO_LIMIT1, &msr);
 
-	fprintf(stderr, "cpu%d: MSR_TURBO_RATIO_LIMIT1: 0x%08llx\n", base_cpu, msr);
+	fprintf(outf, "cpu%d: MSR_TURBO_RATIO_LIMIT1: 0x%08llx\n", base_cpu, msr);
 
 	ratio = (msr >> 56) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 16 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 16 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 48) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 15 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 15 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 40) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 14 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 14 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 32) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 13 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 13 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 24) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 12 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 12 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 16) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 11 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 11 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 8) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 10 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 10 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 0) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 9 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 9 active cores\n",
 			ratio, bclk, ratio * bclk);
 	return;
 }
@@ -1274,46 +1425,46 @@ dump_nhm_turbo_ratio_limits(void)
 
 	get_msr(base_cpu, MSR_TURBO_RATIO_LIMIT, &msr);
 
-	fprintf(stderr, "cpu%d: MSR_TURBO_RATIO_LIMIT: 0x%08llx\n", base_cpu, msr);
+	fprintf(outf, "cpu%d: MSR_TURBO_RATIO_LIMIT: 0x%08llx\n", base_cpu, msr);
 
 	ratio = (msr >> 56) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 8 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 8 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 48) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 7 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 7 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 40) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 6 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 6 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 32) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 5 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 5 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 24) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 4 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 4 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 16) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 3 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 3 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 8) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 2 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 2 active cores\n",
 			ratio, bclk, ratio * bclk);
 
 	ratio = (msr >> 0) & 0xFF;
 	if (ratio)
-		fprintf(stderr, "%d * %.0f = %.0f MHz max turbo 1 active cores\n",
+		fprintf(outf, "%d * %.0f = %.0f MHz max turbo 1 active cores\n",
 			ratio, bclk, ratio * bclk);
 	return;
 }
@@ -1321,21 +1472,23 @@ dump_nhm_turbo_ratio_limits(void)
 static void
 dump_knl_turbo_ratio_limits(void)
 {
-	int cores;
-	unsigned int ratio;
+	const unsigned int buckets_no = 7;
+
 	unsigned long long msr;
-	int delta_cores;
-	int delta_ratio;
-	int i;
+	int delta_cores, delta_ratio;
+	int i, b_nr;
+	unsigned int cores[buckets_no];
+	unsigned int ratio[buckets_no];
 
 	get_msr(base_cpu, MSR_NHM_TURBO_RATIO_LIMIT, &msr);
 
-	fprintf(stderr, "cpu%d: MSR_NHM_TURBO_RATIO_LIMIT: 0x%08llx\n",
+	fprintf(outf, "cpu%d: MSR_TURBO_RATIO_LIMIT: 0x%08llx\n",
 		base_cpu, msr);
 
 	/**
 	 * Turbo encoding in KNL is as follows:
-	 * [7:0] -- Base value of number of active cores of bucket 1.
+	 * [0] -- Reserved
+	 * [7:1] -- Base value of number of active cores of bucket 1.
 	 * [15:8] -- Base value of freq ratio of bucket 1.
 	 * [20:16] -- +ve delta of number of active cores of bucket 2.
 	 * i.e. active cores of bucket 2 =
@@ -1354,29 +1507,25 @@ dump_knl_turbo_ratio_limits(void)
 	 * [60:56]-- +ve delta of number of active cores of bucket 7.
 	 * [63:61]-- -ve delta of freq ratio of bucket 7.
 	 */
-	cores = msr & 0xFF;
-	ratio = (msr >> 8) && 0xFF;
-	if (ratio > 0)
-		fprintf(stderr,
-			"%d * %.0f = %.0f MHz max turbo %d active cores\n",
-			ratio, bclk, ratio * bclk, cores);
-
-	for (i = 16; i < 64; i = i + 8) {
+
+	b_nr = 0;
+	cores[b_nr] = (msr & 0xFF) >> 1;
+	ratio[b_nr] = (msr >> 8) & 0xFF;
+
+	for (i = 16; i < 64; i += 8) {
 		delta_cores = (msr >> i) & 0x1F;
-		delta_ratio = (msr >> (i + 5)) && 0x7;
-		if (!delta_cores || !delta_ratio)
-			return;
-		cores = cores + delta_cores;
-		ratio = ratio - delta_ratio;
-
-		/** -ve ratios will make successive ratio calculations
-		 * negative. Hence return instead of carrying on.
-		 */
-		if (ratio > 0)
-			fprintf(stderr,
-				"%d * %.0f = %.0f MHz max turbo %d active cores\n",
-				ratio, bclk, ratio * bclk, cores);
+		delta_ratio = (msr >> (i + 5)) & 0x7;
+
+		cores[b_nr + 1] = cores[b_nr] + delta_cores;
+		ratio[b_nr + 1] = ratio[b_nr] - delta_ratio;
+		b_nr++;
 	}
+
+	for (i = buckets_no - 1; i >= 0; i--)
+		if (i > 0 ? ratio[i] != ratio[i - 1] : 1)
+			fprintf(outf,
+				"%d * %.0f = %.0f MHz max turbo %d active cores\n",
+				ratio[i], bclk, ratio[i] * bclk, cores[i]);
 }
 
 static void
@@ -1389,15 +1538,15 @@ dump_nhm_cst_cfg(void)
 #define SNB_C1_AUTO_UNDEMOTE              (1UL << 27)
 #define SNB_C3_AUTO_UNDEMOTE              (1UL << 28)
 
-	fprintf(stderr, "cpu%d: MSR_NHM_SNB_PKG_CST_CFG_CTL: 0x%08llx", base_cpu, msr);
+	fprintf(outf, "cpu%d: MSR_NHM_SNB_PKG_CST_CFG_CTL: 0x%08llx", base_cpu, msr);
 
-	fprintf(stderr, " (%s%s%s%s%slocked: pkg-cstate-limit=%d: %s)\n",
+	fprintf(outf, " (%s%s%s%s%slocked: pkg-cstate-limit=%d: %s)\n",
 		(msr & SNB_C3_AUTO_UNDEMOTE) ? "UNdemote-C3, " : "",
 		(msr & SNB_C1_AUTO_UNDEMOTE) ? "UNdemote-C1, " : "",
 		(msr & NHM_C3_AUTO_DEMOTE) ? "demote-C3, " : "",
 		(msr & NHM_C1_AUTO_DEMOTE) ? "demote-C1, " : "",
 		(msr & (1 << 15)) ? "" : "UN",
-		(unsigned int)msr & 7,
+		(unsigned int)msr & 0xF,
 		pkg_cstate_limit_strings[pkg_cstate_limit]);
 	return;
 }
@@ -1408,48 +1557,100 @@ dump_config_tdp(void)
 	unsigned long long msr;
 
 	get_msr(base_cpu, MSR_CONFIG_TDP_NOMINAL, &msr);
-	fprintf(stderr, "cpu%d: MSR_CONFIG_TDP_NOMINAL: 0x%08llx", base_cpu, msr);
-	fprintf(stderr, " (base_ratio=%d)\n", (unsigned int)msr & 0xEF);
+	fprintf(outf, "cpu%d: MSR_CONFIG_TDP_NOMINAL: 0x%08llx", base_cpu, msr);
+	fprintf(outf, " (base_ratio=%d)\n", (unsigned int)msr & 0xFF);
 
 	get_msr(base_cpu, MSR_CONFIG_TDP_LEVEL_1, &msr);
-	fprintf(stderr, "cpu%d: MSR_CONFIG_TDP_LEVEL_1: 0x%08llx (", base_cpu, msr);
+	fprintf(outf, "cpu%d: MSR_CONFIG_TDP_LEVEL_1: 0x%08llx (", base_cpu, msr);
 	if (msr) {
-		fprintf(stderr, "PKG_MIN_PWR_LVL1=%d ", (unsigned int)(msr >> 48) & 0xEFFF);
-		fprintf(stderr, "PKG_MAX_PWR_LVL1=%d ", (unsigned int)(msr >> 32) & 0xEFFF);
-		fprintf(stderr, "LVL1_RATIO=%d ", (unsigned int)(msr >> 16) & 0xEF);
-		fprintf(stderr, "PKG_TDP_LVL1=%d", (unsigned int)(msr) & 0xEFFF);
+		fprintf(outf, "PKG_MIN_PWR_LVL1=%d ", (unsigned int)(msr >> 48) & 0x7FFF);
+		fprintf(outf, "PKG_MAX_PWR_LVL1=%d ", (unsigned int)(msr >> 32) & 0x7FFF);
+		fprintf(outf, "LVL1_RATIO=%d ", (unsigned int)(msr >> 16) & 0xFF);
+		fprintf(outf, "PKG_TDP_LVL1=%d", (unsigned int)(msr) & 0x7FFF);
 	}
-	fprintf(stderr, ")\n");
+	fprintf(outf, ")\n");
 
 	get_msr(base_cpu, MSR_CONFIG_TDP_LEVEL_2, &msr);
-	fprintf(stderr, "cpu%d: MSR_CONFIG_TDP_LEVEL_2: 0x%08llx (", base_cpu, msr);
+	fprintf(outf, "cpu%d: MSR_CONFIG_TDP_LEVEL_2: 0x%08llx (", base_cpu, msr);
 	if (msr) {
-		fprintf(stderr, "PKG_MIN_PWR_LVL2=%d ", (unsigned int)(msr >> 48) & 0xEFFF);
-		fprintf(stderr, "PKG_MAX_PWR_LVL2=%d ", (unsigned int)(msr >> 32) & 0xEFFF);
-		fprintf(stderr, "LVL2_RATIO=%d ", (unsigned int)(msr >> 16) & 0xEF);
-		fprintf(stderr, "PKG_TDP_LVL2=%d", (unsigned int)(msr) & 0xEFFF);
+		fprintf(outf, "PKG_MIN_PWR_LVL2=%d ", (unsigned int)(msr >> 48) & 0x7FFF);
+		fprintf(outf, "PKG_MAX_PWR_LVL2=%d ", (unsigned int)(msr >> 32) & 0x7FFF);
+		fprintf(outf, "LVL2_RATIO=%d ", (unsigned int)(msr >> 16) & 0xFF);
+		fprintf(outf, "PKG_TDP_LVL2=%d", (unsigned int)(msr) & 0x7FFF);
 	}
-	fprintf(stderr, ")\n");
+	fprintf(outf, ")\n");
 
 	get_msr(base_cpu, MSR_CONFIG_TDP_CONTROL, &msr);
-	fprintf(stderr, "cpu%d: MSR_CONFIG_TDP_CONTROL: 0x%08llx (", base_cpu, msr);
+	fprintf(outf, "cpu%d: MSR_CONFIG_TDP_CONTROL: 0x%08llx (", base_cpu, msr);
 	if ((msr) & 0x3)
-		fprintf(stderr, "TDP_LEVEL=%d ", (unsigned int)(msr) & 0x3);
-	fprintf(stderr, " lock=%d", (unsigned int)(msr >> 31) & 1);
-	fprintf(stderr, ")\n");
-	
+		fprintf(outf, "TDP_LEVEL=%d ", (unsigned int)(msr) & 0x3);
+	fprintf(outf, " lock=%d", (unsigned int)(msr >> 31) & 1);
+	fprintf(outf, ")\n");
+
 	get_msr(base_cpu, MSR_TURBO_ACTIVATION_RATIO, &msr);
-	fprintf(stderr, "cpu%d: MSR_TURBO_ACTIVATION_RATIO: 0x%08llx (", base_cpu, msr);
-	fprintf(stderr, "MAX_NON_TURBO_RATIO=%d", (unsigned int)(msr) & 0x7F);
-	fprintf(stderr, " lock=%d", (unsigned int)(msr >> 31) & 1);
-	fprintf(stderr, ")\n");
+	fprintf(outf, "cpu%d: MSR_TURBO_ACTIVATION_RATIO: 0x%08llx (", base_cpu, msr);
+	fprintf(outf, "MAX_NON_TURBO_RATIO=%d", (unsigned int)(msr) & 0xFF);
+	fprintf(outf, " lock=%d", (unsigned int)(msr >> 31) & 1);
+	fprintf(outf, ")\n");
+}
+
+unsigned int irtl_time_units[] = {1, 32, 1024, 32768, 1048576, 33554432, 0, 0 };
+
+void print_irtl(void)
+{
+	unsigned long long msr;
+
+	get_msr(base_cpu, MSR_PKGC3_IRTL, &msr);
+	fprintf(outf, "cpu%d: MSR_PKGC3_IRTL: 0x%08llx (", base_cpu, msr);
+	fprintf(outf, "%svalid, %lld ns)\n", msr & (1 << 15) ? "" : "NOT",
+		(msr & 0x3FF) * irtl_time_units[(msr >> 10) & 0x3]);
+
+	get_msr(base_cpu, MSR_PKGC6_IRTL, &msr);
+	fprintf(outf, "cpu%d: MSR_PKGC6_IRTL: 0x%08llx (", base_cpu, msr);
+	fprintf(outf, "%svalid, %lld ns)\n", msr & (1 << 15) ? "" : "NOT",
+		(msr & 0x3FF) * irtl_time_units[(msr >> 10) & 0x3]);
+
+	get_msr(base_cpu, MSR_PKGC7_IRTL, &msr);
+	fprintf(outf, "cpu%d: MSR_PKGC7_IRTL: 0x%08llx (", base_cpu, msr);
+	fprintf(outf, "%svalid, %lld ns)\n", msr & (1 << 15) ? "" : "NOT",
+		(msr & 0x3FF) * irtl_time_units[(msr >> 10) & 0x3]);
+
+	if (!do_irtl_hsw)
+		return;
+
+	get_msr(base_cpu, MSR_PKGC8_IRTL, &msr);
+	fprintf(outf, "cpu%d: MSR_PKGC8_IRTL: 0x%08llx (", base_cpu, msr);
+	fprintf(outf, "%svalid, %lld ns)\n", msr & (1 << 15) ? "" : "NOT",
+		(msr & 0x3FF) * irtl_time_units[(msr >> 10) & 0x3]);
+
+	get_msr(base_cpu, MSR_PKGC9_IRTL, &msr);
+	fprintf(outf, "cpu%d: MSR_PKGC9_IRTL: 0x%08llx (", base_cpu, msr);
+	fprintf(outf, "%svalid, %lld ns)\n", msr & (1 << 15) ? "" : "NOT",
+		(msr & 0x3FF) * irtl_time_units[(msr >> 10) & 0x3]);
+
+	get_msr(base_cpu, MSR_PKGC10_IRTL, &msr);
+	fprintf(outf, "cpu%d: MSR_PKGC10_IRTL: 0x%08llx (", base_cpu, msr);
+	fprintf(outf, "%svalid, %lld ns)\n", msr & (1 << 15) ? "" : "NOT",
+		(msr & 0x3FF) * irtl_time_units[(msr >> 10) & 0x3]);
+
+}
+void free_fd_percpu(void)
+{
+	int i;
+
+	for (i = 0; i < topo.max_cpu_num; ++i) {
+		if (fd_percpu[i] != 0)
+			close(fd_percpu[i]);
+	}
+
+	free(fd_percpu);
 }
 
 void free_all_buffers(void)
 {
 	CPU_FREE(cpu_present_set);
 	cpu_present_set = NULL;
-	cpu_present_set = 0;
+	cpu_present_setsize = 0;
 
 	CPU_FREE(cpu_affinity_set);
 	cpu_affinity_set = NULL;
@@ -1474,6 +1675,11 @@ void free_all_buffers(void)
 	free(output_buffer);
 	output_buffer = NULL;
 	outp = NULL;
+
+	free_fd_percpu();
+
+	free(irq_column_2_cpu);
+	free(irqs_per_cpu);
 }
 
 /*
@@ -1481,7 +1687,7 @@ void free_all_buffers(void)
  */
 FILE *fopen_or_die(const char *path, const char *mode)
 {
-	FILE *filep = fopen(path, "r");
+	FILE *filep = fopen(path, mode);
 	if (!filep)
 		err(1, "%s: open failed", path);
 	return filep;
@@ -1696,6 +1902,136 @@ int mark_cpu_present(int cpu)
 	return 0;
 }
 
+/*
+ * snapshot_proc_interrupts()
+ *
+ * read and record summary of /proc/interrupts
+ *
+ * return 1 if config change requires a restart, else return 0
+ */
+int snapshot_proc_interrupts(void)
+{
+	static FILE *fp;
+	int column, retval;
+
+	if (fp == NULL)
+		fp = fopen_or_die("/proc/interrupts", "r");
+	else
+		rewind(fp);
+
+	/* read 1st line of /proc/interrupts to get cpu* name for each column */
+	for (column = 0; column < topo.num_cpus; ++column) {
+		int cpu_number;
+
+		retval = fscanf(fp, " CPU%d", &cpu_number);
+		if (retval != 1)
+			break;
+
+		if (cpu_number > topo.max_cpu_num) {
+			warn("/proc/interrupts: cpu%d: > %d", cpu_number, topo.max_cpu_num);
+			return 1;
+		}
+
+		irq_column_2_cpu[column] = cpu_number;
+		irqs_per_cpu[cpu_number] = 0;
+	}
+
+	/* read /proc/interrupt count lines and sum up irqs per cpu */
+	while (1) {
+		int column;
+		char buf[64];
+
+		retval = fscanf(fp, " %s:", buf);	/* flush irq# "N:" */
+		if (retval != 1)
+			break;
+
+		/* read the count per cpu */
+		for (column = 0; column < topo.num_cpus; ++column) {
+
+			int cpu_number, irq_count;
+
+			retval = fscanf(fp, " %d", &irq_count);
+			if (retval != 1)
+				break;
+
+			cpu_number = irq_column_2_cpu[column];
+			irqs_per_cpu[cpu_number] += irq_count;
+
+		}
+
+		while (getc(fp) != '\n')
+			;	/* flush interrupt description */
+
+	}
+	return 0;
+}
+/*
+ * snapshot_gfx_rc6_ms()
+ *
+ * record snapshot of
+ * /sys/class/drm/card0/power/rc6_residency_ms
+ *
+ * return 1 if config change requires a restart, else return 0
+ */
+int snapshot_gfx_rc6_ms(void)
+{
+	FILE *fp;
+	int retval;
+
+	fp = fopen_or_die("/sys/class/drm/card0/power/rc6_residency_ms", "r");
+
+	retval = fscanf(fp, "%lld", &gfx_cur_rc6_ms);
+	if (retval != 1)
+		err(1, "GFX rc6");
+
+	fclose(fp);
+
+	return 0;
+}
+/*
+ * snapshot_gfx_mhz()
+ *
+ * record snapshot of
+ * /sys/class/graphics/fb0/device/drm/card0/gt_cur_freq_mhz
+ *
+ * return 1 if config change requires a restart, else return 0
+ */
+int snapshot_gfx_mhz(void)
+{
+	static FILE *fp;
+	int retval;
+
+	if (fp == NULL)
+		fp = fopen_or_die("/sys/class/graphics/fb0/device/drm/card0/gt_cur_freq_mhz", "r");
+	else
+		rewind(fp);
+
+	retval = fscanf(fp, "%d", &gfx_cur_mhz);
+	if (retval != 1)
+		err(1, "GFX MHz");
+
+	return 0;
+}
+
+/*
+ * snapshot /proc and /sys files
+ *
+ * return 1 if configuration restart needed, else return 0
+ */
+int snapshot_proc_sysfs_files(void)
+{
+	if (snapshot_proc_interrupts())
+		return 1;
+
+	if (do_gfx_rc6_ms)
+		snapshot_gfx_rc6_ms();
+
+	if (do_gfx_mhz)
+		snapshot_gfx_mhz();
+
+	return 0;
+}
+
 void turbostat_loop()
 {
 	int retval;
@@ -1704,6 +2040,7 @@ void turbostat_loop()
 restart:
 	restarted++;
 
+	snapshot_proc_sysfs_files();
 	retval = for_all_cpus(get_counters, EVEN_COUNTERS);
 	if (retval < -1) {
 		exit(retval);
@@ -1722,7 +2059,9 @@ restart:
 			re_initialize();
 			goto restart;
 		}
-		sleep(interval_sec);
+		nanosleep(&interval_ts, NULL);
+		if (snapshot_proc_sysfs_files())
+			goto restart;
 		retval = for_all_cpus(get_counters, ODD_COUNTERS);
 		if (retval < -1) {
 			exit(retval);
@@ -1735,8 +2074,10 @@ restart:
 		for_all_cpus_2(delta_cpu, ODD_COUNTERS, EVEN_COUNTERS);
 		compute_average(EVEN_COUNTERS);
 		format_all_counters(EVEN_COUNTERS);
-		flush_stdout();
-		sleep(interval_sec);
+		flush_output_stdout();
+		nanosleep(&interval_ts, NULL);
+		if (snapshot_proc_sysfs_files())
+			goto restart;
 		retval = for_all_cpus(get_counters, EVEN_COUNTERS);
 		if (retval < -1) {
 			exit(retval);
@@ -1749,7 +2090,7 @@ restart:
 		for_all_cpus_2(delta_cpu, EVEN_COUNTERS, ODD_COUNTERS);
 		compute_average(ODD_COUNTERS);
 		format_all_counters(ODD_COUNTERS);
-		flush_stdout();
+		flush_output_stdout();
 	}
 }
 
@@ -1858,6 +2199,9 @@ int probe_nhm_msrs(unsigned int family, unsigned int model)
 	case 0x56:	/* BDX-DE */
 	case 0x4E:	/* SKL */
 	case 0x5E:	/* SKL */
+	case 0x8E:	/* KBL */
+	case 0x9E:	/* KBL */
+	case 0x55:	/* SKX */
 		pkg_cstate_limits = hsw_pkg_cstate_limits;
 		break;
 	case 0x37:	/* BYT */
@@ -1870,6 +2214,9 @@ int probe_nhm_msrs(unsigned int family, unsigned int model)
 	case 0x57:	/* PHI */
 		pkg_cstate_limits = phi_pkg_cstate_limits;
 		break;
+	case 0x5C:	/* BXT */
+		pkg_cstate_limits = bxt_pkg_cstate_limits;
+		break;
 	default:
 		return 0;
 	}
@@ -1889,6 +2236,7 @@ int has_nhm_turbo_ratio_limit(unsigned int family, unsigned int model)
 	/* Nehalem compatible, but do not include turbo-ratio limit support */
 	case 0x2E:	/* Nehalem-EX Xeon - Beckton */
 	case 0x2F:	/* Westmere-EX Xeon - Eagleton */
+	case 0x57:	/* PHI - Knights Landing (different MSR definition) */
 		return 0;
 	default:
 		return 1;
@@ -1961,6 +2309,9 @@ int has_config_tdp(unsigned int family, unsigned int model)
 	case 0x56:	/* BDX-DE */
 	case 0x4E:	/* SKL */
 	case 0x5E:	/* SKL */
+	case 0x8E:	/* KBL */
+	case 0x9E:	/* KBL */
+	case 0x55:	/* SKX */
 
 	case 0x57:	/* Knights Landing */
 		return 1;
@@ -1970,7 +2321,7 @@ int has_config_tdp(unsigned int family, unsigned int model)
 }
 
 static void
-dump_cstate_pstate_config_info(family, model)
+dump_cstate_pstate_config_info(unsigned int family, unsigned int model)
 {
 	if (!do_nhm_platform_info)
 		return;
@@ -2016,7 +2367,7 @@ int print_epb(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 		return 0;
 
 	if (cpu_migrate(cpu)) {
-		fprintf(stderr, "Could not migrate to CPU %d\n", cpu);
+		fprintf(outf, "Could not migrate to CPU %d\n", cpu);
 		return -1;
 	}
 
@@ -2037,7 +2388,98 @@ int print_epb(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 		epb_string = "custom";
 		break;
 	}
-	fprintf(stderr, "cpu%d: MSR_IA32_ENERGY_PERF_BIAS: 0x%08llx (%s)\n", cpu, msr, epb_string);
+	fprintf(outf, "cpu%d: MSR_IA32_ENERGY_PERF_BIAS: 0x%08llx (%s)\n", cpu, msr, epb_string);
+
+	return 0;
+}
+/*
+ * print_hwp()
+ * Decode the MSR_HWP_CAPABILITIES
+ */
+int print_hwp(struct thread_data *t, struct core_data *c, struct pkg_data *p)
+{
+	unsigned long long msr;
+	int cpu;
+
+	if (!has_hwp)
+		return 0;
+
+	cpu = t->cpu_id;
+
+	/* MSR_HWP_CAPABILITIES is per-package */
+	if (!(t->flags & CPU_IS_FIRST_THREAD_IN_CORE) || !(t->flags & CPU_IS_FIRST_CORE_IN_PACKAGE))
+		return 0;
+
+	if (cpu_migrate(cpu)) {
+		fprintf(outf, "Could not migrate to CPU %d\n", cpu);
+		return -1;
+	}
+
+	if (get_msr(cpu, MSR_PM_ENABLE, &msr))
+		return 0;
+
+	fprintf(outf, "cpu%d: MSR_PM_ENABLE: 0x%08llx (%sHWP)\n",
+		cpu, msr, (msr & (1 << 0)) ? "" : "No-");
+
+	/* MSR_PM_ENABLE[1] == 1 if HWP is enabled and MSRs visible */
+	if ((msr & (1 << 0)) == 0)
+		return 0;
+
+	if (get_msr(cpu, MSR_HWP_CAPABILITIES, &msr))
+		return 0;
+
+	fprintf(outf, "cpu%d: MSR_HWP_CAPABILITIES: 0x%08llx "
+			"(high 0x%x guar 0x%x eff 0x%x low 0x%x)\n",
+			cpu, msr,
+			(unsigned int)HWP_HIGHEST_PERF(msr),
+			(unsigned int)HWP_GUARANTEED_PERF(msr),
+			(unsigned int)HWP_MOSTEFFICIENT_PERF(msr),
+			(unsigned int)HWP_LOWEST_PERF(msr));
+
+	if (get_msr(cpu, MSR_HWP_REQUEST, &msr))
+		return 0;
+
+	fprintf(outf, "cpu%d: MSR_HWP_REQUEST: 0x%08llx "
+			"(min 0x%x max 0x%x des 0x%x epp 0x%x window 0x%x pkg 0x%x)\n",
+			cpu, msr,
+			(unsigned int)(((msr) >> 0) & 0xff),
+			(unsigned int)(((msr) >> 8) & 0xff),
+			(unsigned int)(((msr) >> 16) & 0xff),
+			(unsigned int)(((msr) >> 24) & 0xff),
+			(unsigned int)(((msr) >> 32) & 0xff3),
+			(unsigned int)(((msr) >> 42) & 0x1));
+
+	if (has_hwp_pkg) {
+		if (get_msr(cpu, MSR_HWP_REQUEST_PKG, &msr))
+			return 0;
+
+		fprintf(outf, "cpu%d: MSR_HWP_REQUEST_PKG: 0x%08llx "
+			"(min 0x%x max 0x%x des 0x%x epp 0x%x window 0x%x)\n",
+			cpu, msr,
+			(unsigned int)(((msr) >> 0) & 0xff),
+			(unsigned int)(((msr) >> 8) & 0xff),
+			(unsigned int)(((msr) >> 16) & 0xff),
+			(unsigned int)(((msr) >> 24) & 0xff),
+			(unsigned int)(((msr) >> 32) & 0xff3));
+	}
+	if (has_hwp_notify) {
+		if (get_msr(cpu, MSR_HWP_INTERRUPT, &msr))
+			return 0;
+
+		fprintf(outf, "cpu%d: MSR_HWP_INTERRUPT: 0x%08llx "
+			"(%s_Guaranteed_Perf_Change, %s_Excursion_Min)\n",
+			cpu, msr,
+			((msr) & 0x1) ? "EN" : "Dis",
+			((msr) & 0x2) ? "EN" : "Dis");
+	}
+	if (get_msr(cpu, MSR_HWP_STATUS, &msr))
+		return 0;
+
+	fprintf(outf, "cpu%d: MSR_HWP_STATUS: 0x%08llx "
+			"(%sGuaranteed_Perf_Change, %sExcursion_Min)\n",
+			cpu, msr,
+			((msr) & 0x1) ? "" : "No-",
+			((msr) & 0x2) ? "" : "No-");
 
 	return 0;
 }
@@ -2057,14 +2499,14 @@ int print_perf_limit(struct thread_data *t, struct core_data *c, struct pkg_data
 		return 0;
 
 	if (cpu_migrate(cpu)) {
-		fprintf(stderr, "Could not migrate to CPU %d\n", cpu);
+		fprintf(outf, "Could not migrate to CPU %d\n", cpu);
 		return -1;
 	}
 
 	if (do_core_perf_limit_reasons) {
 		get_msr(cpu, MSR_CORE_PERF_LIMIT_REASONS, &msr);
-		fprintf(stderr, "cpu%d: MSR_CORE_PERF_LIMIT_REASONS, 0x%08llx", cpu, msr);
-		fprintf(stderr, " (Active: %s%s%s%s%s%s%s%s%s%s%s%s%s%s)",
+		fprintf(outf, "cpu%d: MSR_CORE_PERF_LIMIT_REASONS, 0x%08llx", cpu, msr);
+		fprintf(outf, " (Active: %s%s%s%s%s%s%s%s%s%s%s%s%s%s)",
 			(msr & 1 << 15) ? "bit15, " : "",
 			(msr & 1 << 14) ? "bit14, " : "",
 			(msr & 1 << 13) ? "Transitions, " : "",
@@ -2079,7 +2521,7 @@ int print_perf_limit(struct thread_data *t, struct core_data *c, struct pkg_data
 			(msr & 1 << 2) ? "bit2, " : "",
 			(msr & 1 << 1) ? "ThermStatus, " : "",
 			(msr & 1 << 0) ? "PROCHOT, " : "");
-		fprintf(stderr, " (Logged: %s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n",
+		fprintf(outf, " (Logged: %s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n",
 			(msr & 1 << 31) ? "bit31, " : "",
 			(msr & 1 << 30) ? "bit30, " : "",
 			(msr & 1 << 29) ? "Transitions, " : "",
@@ -2098,8 +2540,8 @@ int print_perf_limit(struct thread_data *t, struct core_data *c, struct pkg_data
 	}
 	if (do_gfx_perf_limit_reasons) {
 		get_msr(cpu, MSR_GFX_PERF_LIMIT_REASONS, &msr);
-		fprintf(stderr, "cpu%d: MSR_GFX_PERF_LIMIT_REASONS, 0x%08llx", cpu, msr);
-		fprintf(stderr, " (Active: %s%s%s%s%s%s%s%s)",
+		fprintf(outf, "cpu%d: MSR_GFX_PERF_LIMIT_REASONS, 0x%08llx", cpu, msr);
+		fprintf(outf, " (Active: %s%s%s%s%s%s%s%s)",
 			(msr & 1 << 0) ? "PROCHOT, " : "",
 			(msr & 1 << 1) ? "ThermStatus, " : "",
 			(msr & 1 << 4) ? "Graphics, " : "",
@@ -2108,7 +2550,7 @@ int print_perf_limit(struct thread_data *t, struct core_data *c, struct pkg_data
 			(msr & 1 << 9) ? "GFXPwr, " : "",
 			(msr & 1 << 10) ? "PkgPwrL1, " : "",
 			(msr & 1 << 11) ? "PkgPwrL2, " : "");
-		fprintf(stderr, " (Logged: %s%s%s%s%s%s%s%s)\n",
+		fprintf(outf, " (Logged: %s%s%s%s%s%s%s%s)\n",
 			(msr & 1 << 16) ? "PROCHOT, " : "",
 			(msr & 1 << 17) ? "ThermStatus, " : "",
 			(msr & 1 << 20) ? "Graphics, " : "",
@@ -2120,15 +2562,15 @@ int print_perf_limit(struct thread_data *t, struct core_data *c, struct pkg_data
 	}
 	if (do_ring_perf_limit_reasons) {
 		get_msr(cpu, MSR_RING_PERF_LIMIT_REASONS, &msr);
-		fprintf(stderr, "cpu%d: MSR_RING_PERF_LIMIT_REASONS, 0x%08llx", cpu, msr);
-		fprintf(stderr, " (Active: %s%s%s%s%s%s)",
+		fprintf(outf, "cpu%d: MSR_RING_PERF_LIMIT_REASONS, 0x%08llx", cpu, msr);
+		fprintf(outf, " (Active: %s%s%s%s%s%s)",
 			(msr & 1 << 0) ? "PROCHOT, " : "",
 			(msr & 1 << 1) ? "ThermStatus, " : "",
 			(msr & 1 << 6) ? "VR-Therm, " : "",
 			(msr & 1 << 8) ? "Amps, " : "",
 			(msr & 1 << 10) ? "PkgPwrL1, " : "",
 			(msr & 1 << 11) ? "PkgPwrL2, " : "");
-		fprintf(stderr, " (Logged: %s%s%s%s%s%s)\n",
+		fprintf(outf, " (Logged: %s%s%s%s%s%s)\n",
 			(msr & 1 << 16) ? "PROCHOT, " : "",
 			(msr & 1 << 17) ? "ThermStatus, " : "",
 			(msr & 1 << 22) ? "VR-Therm, " : "",
@@ -2142,7 +2584,7 @@ int print_perf_limit(struct thread_data *t, struct core_data *c, struct pkg_data
 #define	RAPL_POWER_GRANULARITY	0x7FFF	/* 15 bit power granularity */
 #define	RAPL_TIME_GRANULARITY	0x3F /* 6 bit time granularity */
 
-double get_tdp(model)
+double get_tdp(unsigned int model)
 {
 	unsigned long long msr;
 
@@ -2207,13 +2649,19 @@ void rapl_probe(unsigned int family, unsigned int model)
 	case 0x47:	/* BDW */
 		do_rapl = RAPL_PKG | RAPL_CORES | RAPL_CORE_POLICY | RAPL_GFX | RAPL_PKG_POWER_INFO;
 		break;
+	case 0x5C:	/* BXT */
+		do_rapl = RAPL_PKG | RAPL_PKG_POWER_INFO;
+		break;
 	case 0x4E:	/* SKL */
 	case 0x5E:	/* SKL */
+	case 0x8E:	/* KBL */
+	case 0x9E:	/* KBL */
 		do_rapl = RAPL_PKG | RAPL_DRAM | RAPL_DRAM_PERF_STATUS | RAPL_PKG_PERF_STATUS | RAPL_PKG_POWER_INFO;
 		break;
 	case 0x3F:	/* HSX */
 	case 0x4F:	/* BDX */
 	case 0x56:	/* BDX-DE */
+	case 0x55:	/* SKX */
 	case 0x57:	/* KNL */
 		do_rapl = RAPL_PKG | RAPL_DRAM | RAPL_DRAM_POWER_INFO | RAPL_DRAM_PERF_STATUS | RAPL_PKG_PERF_STATUS | RAPL_PKG_POWER_INFO;
 		break;
@@ -2251,12 +2699,12 @@ void rapl_probe(unsigned int family, unsigned int model)
 
 	rapl_joule_counter_range = 0xFFFFFFFF * rapl_energy_units / tdp;
 	if (debug)
-		fprintf(stderr, "RAPL: %.0f sec. Joule Counter Range, at %.0f Watts\n", rapl_joule_counter_range, tdp);
+		fprintf(outf, "RAPL: %.0f sec. Joule Counter Range, at %.0f Watts\n", rapl_joule_counter_range, tdp);
 
 	return;
 }
 
-void perf_limit_reasons_probe(family, model)
+void perf_limit_reasons_probe(unsigned int family, unsigned int model)
 {
 	if (!genuine_intel)
 		return;
@@ -2293,7 +2741,7 @@ int print_thermal(struct thread_data *t, struct core_data *c, struct pkg_data *p
 		return 0;
 
 	if (cpu_migrate(cpu)) {
-		fprintf(stderr, "Could not migrate to CPU %d\n", cpu);
+		fprintf(outf, "Could not migrate to CPU %d\n", cpu);
 		return -1;
 	}
 
@@ -2302,7 +2750,7 @@ int print_thermal(struct thread_data *t, struct core_data *c, struct pkg_data *p
 			return 0;
 
 		dts = (msr >> 16) & 0x7F;
-		fprintf(stderr, "cpu%d: MSR_IA32_PACKAGE_THERM_STATUS: 0x%08llx (%d C)\n",
+		fprintf(outf, "cpu%d: MSR_IA32_PACKAGE_THERM_STATUS: 0x%08llx (%d C)\n",
 			cpu, msr, tcc_activation_temp - dts);
 
 #ifdef	THERM_DEBUG
@@ -2311,7 +2759,7 @@ int print_thermal(struct thread_data *t, struct core_data *c, struct pkg_data *p
 
 		dts = (msr >> 16) & 0x7F;
 		dts2 = (msr >> 8) & 0x7F;
-		fprintf(stderr, "cpu%d: MSR_IA32_PACKAGE_THERM_INTERRUPT: 0x%08llx (%d C, %d C)\n",
+		fprintf(outf, "cpu%d: MSR_IA32_PACKAGE_THERM_INTERRUPT: 0x%08llx (%d C, %d C)\n",
 			cpu, msr, tcc_activation_temp - dts, tcc_activation_temp - dts2);
 #endif
 	}
@@ -2325,7 +2773,7 @@ int print_thermal(struct thread_data *t, struct core_data *c, struct pkg_data *p
 
 		dts = (msr >> 16) & 0x7F;
 		resolution = (msr >> 27) & 0xF;
-		fprintf(stderr, "cpu%d: MSR_IA32_THERM_STATUS: 0x%08llx (%d C +/- %d)\n",
+		fprintf(outf, "cpu%d: MSR_IA32_THERM_STATUS: 0x%08llx (%d C +/- %d)\n",
 			cpu, msr, tcc_activation_temp - dts, resolution);
 
 #ifdef THERM_DEBUG
@@ -2334,17 +2782,17 @@ int print_thermal(struct thread_data *t, struct core_data *c, struct pkg_data *p
 
 		dts = (msr >> 16) & 0x7F;
 		dts2 = (msr >> 8) & 0x7F;
-		fprintf(stderr, "cpu%d: MSR_IA32_THERM_INTERRUPT: 0x%08llx (%d C, %d C)\n",
+		fprintf(outf, "cpu%d: MSR_IA32_THERM_INTERRUPT: 0x%08llx (%d C, %d C)\n",
 			cpu, msr, tcc_activation_temp - dts, tcc_activation_temp - dts2);
 #endif
 	}
 
 	return 0;
 }
-	
+
 void print_power_limit_msr(int cpu, unsigned long long msr, char *label)
 {
-	fprintf(stderr, "cpu%d: %s: %sabled (%f Watts, %f sec, clamp %sabled)\n",
+	fprintf(outf, "cpu%d: %s: %sabled (%f Watts, %f sec, clamp %sabled)\n",
 		cpu, label,
 		((msr >> 15) & 1) ? "EN" : "DIS",
 		((msr >> 0) & 0x7FFF) * rapl_power_units,
@@ -2368,7 +2816,7 @@ int print_rapl(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 
 	cpu = t->cpu_id;
 	if (cpu_migrate(cpu)) {
-		fprintf(stderr, "Could not migrate to CPU %d\n", cpu);
+		fprintf(outf, "Could not migrate to CPU %d\n", cpu);
 		return -1;
 	}
 
@@ -2376,7 +2824,7 @@ int print_rapl(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 		return -1;
 
 	if (debug) {
-		fprintf(stderr, "cpu%d: MSR_RAPL_POWER_UNIT: 0x%08llx "
+		fprintf(outf, "cpu%d: MSR_RAPL_POWER_UNIT: 0x%08llx "
 			"(%f Watts, %f Joules, %f sec.)\n", cpu, msr,
 			rapl_power_units, rapl_energy_units, rapl_time_units);
 	}
@@ -2386,7 +2834,7 @@ int print_rapl(struct thread_data *t, struct core_data *c, struct pkg_data *p)
                 	return -5;
 
 
-		fprintf(stderr, "cpu%d: MSR_PKG_POWER_INFO: 0x%08llx (%.0f W TDP, RAPL %.0f - %.0f W, %f sec.)\n",
+		fprintf(outf, "cpu%d: MSR_PKG_POWER_INFO: 0x%08llx (%.0f W TDP, RAPL %.0f - %.0f W, %f sec.)\n",
 			cpu, msr,
 			((msr >>  0) & RAPL_POWER_GRANULARITY) * rapl_power_units,
 			((msr >> 16) & RAPL_POWER_GRANULARITY) * rapl_power_units,
@@ -2399,11 +2847,11 @@ int print_rapl(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 		if (get_msr(cpu, MSR_PKG_POWER_LIMIT, &msr))
 			return -9;
 
-		fprintf(stderr, "cpu%d: MSR_PKG_POWER_LIMIT: 0x%08llx (%slocked)\n",
+		fprintf(outf, "cpu%d: MSR_PKG_POWER_LIMIT: 0x%08llx (%slocked)\n",
 			cpu, msr, (msr >> 63) & 1 ? "": "UN");
 
 		print_power_limit_msr(cpu, msr, "PKG Limit #1");
-		fprintf(stderr, "cpu%d: PKG Limit #2: %sabled (%f Watts, %f* sec, clamp %sabled)\n",
+		fprintf(outf, "cpu%d: PKG Limit #2: %sabled (%f Watts, %f* sec, clamp %sabled)\n",
 			cpu,
 			((msr >> 47) & 1) ? "EN" : "DIS",
 			((msr >> 32) & 0x7FFF) * rapl_power_units,
@@ -2415,7 +2863,7 @@ int print_rapl(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 		if (get_msr(cpu, MSR_DRAM_POWER_INFO, &msr))
                 	return -6;
 
-		fprintf(stderr, "cpu%d: MSR_DRAM_POWER_INFO,: 0x%08llx (%.0f W TDP, RAPL %.0f - %.0f W, %f sec.)\n",
+		fprintf(outf, "cpu%d: MSR_DRAM_POWER_INFO,: 0x%08llx (%.0f W TDP, RAPL %.0f - %.0f W, %f sec.)\n",
 			cpu, msr,
 			((msr >>  0) & RAPL_POWER_GRANULARITY) * rapl_power_units,
 			((msr >> 16) & RAPL_POWER_GRANULARITY) * rapl_power_units,
@@ -2425,7 +2873,7 @@ int print_rapl(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 	if (do_rapl & RAPL_DRAM) {
 		if (get_msr(cpu, MSR_DRAM_POWER_LIMIT, &msr))
 			return -9;
-		fprintf(stderr, "cpu%d: MSR_DRAM_POWER_LIMIT: 0x%08llx (%slocked)\n",
+		fprintf(outf, "cpu%d: MSR_DRAM_POWER_LIMIT: 0x%08llx (%slocked)\n",
 				cpu, msr, (msr >> 31) & 1 ? "": "UN");
 
 		print_power_limit_msr(cpu, msr, "DRAM Limit");
@@ -2435,7 +2883,7 @@ int print_rapl(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 			if (get_msr(cpu, MSR_PP0_POLICY, &msr))
 				return -7;
 
-			fprintf(stderr, "cpu%d: MSR_PP0_POLICY: %lld\n", cpu, msr & 0xF);
+			fprintf(outf, "cpu%d: MSR_PP0_POLICY: %lld\n", cpu, msr & 0xF);
 		}
 	}
 	if (do_rapl & RAPL_CORES) {
@@ -2443,7 +2891,7 @@ int print_rapl(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 
 			if (get_msr(cpu, MSR_PP0_POWER_LIMIT, &msr))
 				return -9;
-			fprintf(stderr, "cpu%d: MSR_PP0_POWER_LIMIT: 0x%08llx (%slocked)\n",
+			fprintf(outf, "cpu%d: MSR_PP0_POWER_LIMIT: 0x%08llx (%slocked)\n",
 					cpu, msr, (msr >> 31) & 1 ? "": "UN");
 			print_power_limit_msr(cpu, msr, "Cores Limit");
 		}
@@ -2453,11 +2901,11 @@ int print_rapl(struct thread_data *t, struct core_data *c, struct pkg_data *p)
 			if (get_msr(cpu, MSR_PP1_POLICY, &msr))
 				return -8;
 
-			fprintf(stderr, "cpu%d: MSR_PP1_POLICY: %lld\n", cpu, msr & 0xF);
+			fprintf(outf, "cpu%d: MSR_PP1_POLICY: %lld\n", cpu, msr & 0xF);
 
 			if (get_msr(cpu, MSR_PP1_POWER_LIMIT, &msr))
 				return -9;
-			fprintf(stderr, "cpu%d: MSR_PP1_POWER_LIMIT: 0x%08llx (%slocked)\n",
+			fprintf(outf, "cpu%d: MSR_PP1_POWER_LIMIT: 0x%08llx (%slocked)\n",
 					cpu, msr, (msr >> 31) & 1 ? "": "UN");
 			print_power_limit_msr(cpu, msr, "GFX Limit");
 		}
@@ -2493,6 +2941,10 @@ int has_snb_msrs(unsigned int family, unsigned int model)
 	case 0x56:	/* BDX-DE */
 	case 0x4E:	/* SKL */
 	case 0x5E:	/* SKL */
+	case 0x8E:	/* KBL */
+	case 0x9E:	/* KBL */
+	case 0x55:	/* SKX */
+	case 0x5C:	/* BXT */
 		return 1;
 	}
 	return 0;
@@ -2501,9 +2953,14 @@ int has_snb_msrs(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
+ * MSR_PKG_C8_RESIDENCY		0x00000630
+ * MSR_PKG_C9_RESIDENCY		0x00000631
+ * MSR_PKG_C10_RESIDENCY	0x00000632
+ *
+ * MSR_PKGC8_IRTL		0x00000633
+ * MSR_PKGC9_IRTL		0x00000634
+ * MSR_PKGC10_IRTL		0x00000635
+ *
  */
 int has_hsw_msrs(unsigned int family, unsigned int model)
 {
@@ -2515,6 +2972,9 @@ int has_hsw_msrs(unsigned int family, unsigned int model)
 	case 0x3D:	/* BDW */
 	case 0x4E:	/* SKL */
 	case 0x5E:	/* SKL */
+	case 0x8E:	/* KBL */
+	case 0x9E:	/* KBL */
+	case 0x5C:	/* BXT */
 		return 1;
 	}
 	return 0;
@@ -2536,6 +2996,8 @@ int has_skl_msrs(unsigned int family, unsigned int model)
 	switch (model) {
 	case 0x4E:	/* SKL */
 	case 0x5E:	/* SKL */
+	case 0x8E:	/* KBL */
+	case 0x9E:	/* KBL */
 		return 1;
 	}
 	return 0;
@@ -2583,23 +3045,23 @@ double slm_bclk(void)
 	double freq;
 
 	if (get_msr(base_cpu, MSR_FSB_FREQ, &msr))
-		fprintf(stderr, "SLM BCLK: unknown\n");
+		fprintf(outf, "SLM BCLK: unknown\n");
 
 	i = msr & 0xf;
 	if (i >= SLM_BCLK_FREQS) {
-		fprintf(stderr, "SLM BCLK[%d] invalid\n", i);
+		fprintf(outf, "SLM BCLK[%d] invalid\n", i);
 		msr = 3;
 	}
 	freq = slm_freq_table[i];
 
-	fprintf(stderr, "SLM BCLK: %.1f Mhz\n", freq);
+	fprintf(outf, "SLM BCLK: %.1f Mhz\n", freq);
 
 	return freq;
 }
 
 double discover_bclk(unsigned int family, unsigned int model)
 {
-	if (has_snb_msrs(family, model))
+	if (has_snb_msrs(family, model) || is_knl(family, model))
 		return 100.00;
 	else if (is_slm(family, model))
 		return slm_bclk();
@@ -2635,13 +3097,13 @@ int set_temperature_target(struct thread_data *t, struct core_data *c, struct pk
 
 	cpu = t->cpu_id;
 	if (cpu_migrate(cpu)) {
-		fprintf(stderr, "Could not migrate to CPU %d\n", cpu);
+		fprintf(outf, "Could not migrate to CPU %d\n", cpu);
 		return -1;
 	}
 
 	if (tcc_activation_temp_override != 0) {
 		tcc_activation_temp = tcc_activation_temp_override;
-		fprintf(stderr, "cpu%d: Using cmdline TCC Target (%d C)\n",
+		fprintf(outf, "cpu%d: Using cmdline TCC Target (%d C)\n",
 			cpu, tcc_activation_temp);
 		return 0;
 	}
@@ -2656,7 +3118,7 @@ int set_temperature_target(struct thread_data *t, struct core_data *c, struct pk
 	target_c_local = (msr >> 16) & 0xFF;
 
 	if (debug)
-		fprintf(stderr, "cpu%d: MSR_IA32_TEMPERATURE_TARGET: 0x%08llx (%d C)\n",
+		fprintf(outf, "cpu%d: MSR_IA32_TEMPERATURE_TARGET: 0x%08llx (%d C)\n",
 			cpu, msr, target_c_local);
 
 	if (!target_c_local)
@@ -2668,37 +3130,93 @@ int set_temperature_target(struct thread_data *t, struct core_data *c, struct pk
 
 guess:
 	tcc_activation_temp = TJMAX_DEFAULT;
-	fprintf(stderr, "cpu%d: Guessing tjMax %d C, Please use -T to specify\n",
+	fprintf(outf, "cpu%d: Guessing tjMax %d C, Please use -T to specify\n",
 		cpu, tcc_activation_temp);
 
 	return 0;
 }
+
+void decode_feature_control_msr(void)
+{
+	unsigned long long msr;
+
+	if (!get_msr(base_cpu, MSR_IA32_FEATURE_CONTROL, &msr))
+		fprintf(outf, "cpu%d: MSR_IA32_FEATURE_CONTROL: 0x%08llx (%sLocked %s)\n",
+			base_cpu, msr,
+			msr & FEATURE_CONTROL_LOCKED ? "" : "UN-",
+			msr & (1 << 18) ? "SGX" : "");
+}
+
+void decode_misc_enable_msr(void)
+{
+	unsigned long long msr;
+
+	if (!get_msr(base_cpu, MSR_IA32_MISC_ENABLE, &msr))
+		fprintf(outf, "cpu%d: MSR_IA32_MISC_ENABLE: 0x%08llx (%s %s %s)\n",
+			base_cpu, msr,
+			msr & (1 << 3) ? "TCC" : "",
+			msr & (1 << 16) ? "EIST" : "",
+			msr & (1 << 18) ? "MONITOR" : "");
+}
+
+/*
+ * Decode MSR_MISC_PWR_MGMT
+ *
+ * Decode the bits according to the Nehalem documentation
+ * bit[0] seems to continue to have same meaning going forward
+ * bit[1] less so...
+ */
+void decode_misc_pwr_mgmt_msr(void)
+{
+	unsigned long long msr;
+
+	if (!do_nhm_platform_info)
+		return;
+
+	if (!get_msr(base_cpu, MSR_MISC_PWR_MGMT, &msr))
+		fprintf(outf, "cpu%d: MSR_MISC_PWR_MGMT: 0x%08llx (%sable-EIST_Coordination %sable-EPB)\n",
+			base_cpu, msr,
+			msr & (1 << 0) ? "DIS" : "EN",
+			msr & (1 << 1) ? "EN" : "DIS");
+}
+
 void process_cpuid()
 {
-	unsigned int eax, ebx, ecx, edx, max_level;
+	unsigned int eax, ebx, ecx, edx, max_level, max_extended_level;
 	unsigned int fms, family, model, stepping;
 
 	eax = ebx = ecx = edx = 0;
 
-	__get_cpuid(0, &max_level, &ebx, &ecx, &edx);
+	__cpuid(0, max_level, ebx, ecx, edx);
 
 	if (ebx == 0x756e6547 && edx == 0x49656e69 && ecx == 0x6c65746e)
 		genuine_intel = 1;
 
 	if (debug)
-		fprintf(stderr, "CPUID(0): %.4s%.4s%.4s ",
+		fprintf(outf, "CPUID(0): %.4s%.4s%.4s ",
 			(char *)&ebx, (char *)&edx, (char *)&ecx);
 
-	__get_cpuid(1, &fms, &ebx, &ecx, &edx);
+	__cpuid(1, fms, ebx, ecx, edx);
 	family = (fms >> 8) & 0xf;
 	model = (fms >> 4) & 0xf;
 	stepping = fms & 0xf;
 	if (family == 6 || family == 0xf)
 		model += ((fms >> 16) & 0xf) << 4;
 
-	if (debug)
-		fprintf(stderr, "%d CPUID levels; family:model:stepping 0x%x:%x:%x (%d:%d:%d)\n",
+	if (debug) {
+		fprintf(outf, "%d CPUID levels; family:model:stepping 0x%x:%x:%x (%d:%d:%d)\n",
 			max_level, family, model, stepping, family, model, stepping);
+		fprintf(outf, "CPUID(1): %s %s %s %s %s %s %s %s %s\n",
+			ecx & (1 << 0) ? "SSE3" : "-",
+			ecx & (1 << 3) ? "MONITOR" : "-",
+			ecx & (1 << 6) ? "SMX" : "-",
+			ecx & (1 << 7) ? "EIST" : "-",
+			ecx & (1 << 8) ? "TM2" : "-",
+			edx & (1 << 4) ? "TSC" : "-",
+			edx & (1 << 5) ? "MSR" : "-",
+			edx & (1 << 22) ? "ACPI-TM" : "-",
+			edx & (1 << 29) ? "TM" : "-");
+	}
 
 	if (!(edx & (1 << 5)))
 		errx(1, "CPUID: no MSR");
@@ -2709,15 +3227,15 @@ void process_cpuid()
 	 * This check is valid for both Intel and AMD.
 	 */
 	ebx = ecx = edx = 0;
-	__get_cpuid(0x80000000, &max_level, &ebx, &ecx, &edx);
+	__cpuid(0x80000000, max_extended_level, ebx, ecx, edx);
 
-	if (max_level >= 0x80000007) {
+	if (max_extended_level >= 0x80000007) {
 
 		/*
 		 * Non-Stop TSC is advertised by CPUID.EAX=0x80000007: EDX.bit8
 		 * this check is valid for both Intel and AMD
 		 */
-		__get_cpuid(0x80000007, &eax, &ebx, &ecx, &edx);
+		__cpuid(0x80000007, eax, ebx, ecx, edx);
 		has_invariant_tsc = edx & (1 << 8);
 	}
 
@@ -2726,20 +3244,48 @@ void process_cpuid()
 	 * this check is valid for both Intel and AMD
 	 */
 
-	__get_cpuid(0x6, &eax, &ebx, &ecx, &edx);
+	__cpuid(0x6, eax, ebx, ecx, edx);
 	has_aperf = ecx & (1 << 0);
 	do_dts = eax & (1 << 0);
 	do_ptm = eax & (1 << 6);
+	has_hwp = eax & (1 << 7);
+	has_hwp_notify = eax & (1 << 8);
+	has_hwp_activity_window = eax & (1 << 9);
+	has_hwp_epp = eax & (1 << 10);
+	has_hwp_pkg = eax & (1 << 11);
 	has_epb = ecx & (1 << 3);
 
 	if (debug)
-		fprintf(stderr, "CPUID(6): %sAPERF, %sDTS, %sPTM, %sEPB\n",
-			has_aperf ? "" : "No ",
-			do_dts ? "" : "No ",
-			do_ptm ? "" : "No ",
-			has_epb ? "" : "No ");
+		fprintf(outf, "CPUID(6): %sAPERF, %sDTS, %sPTM, %sHWP, "
+			"%sHWPnotify, %sHWPwindow, %sHWPepp, %sHWPpkg, %sEPB\n",
+			has_aperf ? "" : "No-",
+			do_dts ? "" : "No-",
+			do_ptm ? "" : "No-",
+			has_hwp ? "" : "No-",
+			has_hwp_notify ? "" : "No-",
+			has_hwp_activity_window ? "" : "No-",
+			has_hwp_epp ? "" : "No-",
+			has_hwp_pkg ? "" : "No-",
+			has_epb ? "" : "No-");
+
+	if (debug)
+		decode_misc_enable_msr();
+
+	if (max_level >= 0x7 && debug) {
+		int has_sgx;
+
+		ecx = 0;
+
+		__cpuid_count(0x7, 0, eax, ebx, ecx, edx);
+
+		has_sgx = ebx & (1 << 2);
+		fprintf(outf, "CPUID(7): %sSGX\n", has_sgx ? "" : "No-");
+
+		if (has_sgx)
+			decode_feature_control_msr();
+	}
 
-	if (max_level > 0x15) {
+	if (max_level >= 0x15) {
 		unsigned int eax_crystal;
 		unsigned int ebx_tsc;
 
@@ -2747,19 +3293,27 @@ void process_cpuid()
 		 * CPUID 15H TSC/Crystal ratio, possibly Crystal Hz
 		 */
 		eax_crystal = ebx_tsc = crystal_hz = edx = 0;
-		__get_cpuid(0x15, &eax_crystal, &ebx_tsc, &crystal_hz, &edx);
+		__cpuid(0x15, eax_crystal, ebx_tsc, crystal_hz, edx);
 
 		if (ebx_tsc != 0) {
 
 			if (debug && (ebx != 0))
-				fprintf(stderr, "CPUID(0x15): eax_crystal: %d ebx_tsc: %d ecx_crystal_hz: %d\n",
+				fprintf(outf, "CPUID(0x15): eax_crystal: %d ebx_tsc: %d ecx_crystal_hz: %d\n",
 					eax_crystal, ebx_tsc, crystal_hz);
 
 			if (crystal_hz == 0)
 				switch(model) {
 				case 0x4E:	/* SKL */
 				case 0x5E:	/* SKL */
-					crystal_hz = 24000000;	/* 24 MHz */
+				case 0x8E:	/* KBL */
+				case 0x9E:	/* KBL */
+					crystal_hz = 24000000;	/* 24.0 MHz */
+					break;
+				case 0x55:	/* SKX */
+					crystal_hz = 25000000;	/* 25.0 MHz */
+					break;
+				case 0x5C:	/* BXT */
+					crystal_hz = 19200000;	/* 19.2 MHz */
 					break;
 				default:
 					crystal_hz = 0;
@@ -2768,41 +3322,63 @@ void process_cpuid()
 			if (crystal_hz) {
 				tsc_hz =  (unsigned long long) crystal_hz * ebx_tsc / eax_crystal;
 				if (debug)
-					fprintf(stderr, "TSC: %lld MHz (%d Hz * %d / %d / 1000000)\n",
+					fprintf(outf, "TSC: %lld MHz (%d Hz * %d / %d / 1000000)\n",
 						tsc_hz / 1000000, crystal_hz, ebx_tsc,  eax_crystal);
 			}
 		}
 	}
+	if (max_level >= 0x16) {
+		unsigned int base_mhz, max_mhz, bus_mhz, edx;
+
+		/*
+		 * CPUID 16H Base MHz, Max MHz, Bus MHz
+		 */
+		base_mhz = max_mhz = bus_mhz = edx = 0;
+
+		__cpuid(0x16, base_mhz, max_mhz, bus_mhz, edx);
+		if (debug)
+			fprintf(outf, "CPUID(0x16): base_mhz: %d max_mhz: %d bus_mhz: %d\n",
+				base_mhz, max_mhz, bus_mhz);
+	}
 
 	if (has_aperf)
 		aperf_mperf_multiplier = get_aperf_mperf_multiplier(family, model);
 
 	do_nhm_platform_info = do_nhm_cstates = do_smi = probe_nhm_msrs(family, model);
 	do_snb_cstates = has_snb_msrs(family, model);
+	do_irtl_snb = has_snb_msrs(family, model);
 	do_pc2 = do_snb_cstates && (pkg_cstate_limit >= PCL__2);
 	do_pc3 = (pkg_cstate_limit >= PCL__3);
 	do_pc6 = (pkg_cstate_limit >= PCL__6);
 	do_pc7 = do_snb_cstates && (pkg_cstate_limit >= PCL__7);
 	do_c8_c9_c10 = has_hsw_msrs(family, model);
+	do_irtl_hsw = has_hsw_msrs(family, model);
 	do_skl_residency = has_skl_msrs(family, model);
 	do_slm_cstates = is_slm(family, model);
 	do_knl_cstates  = is_knl(family, model);
 
+	if (debug)
+		decode_misc_pwr_mgmt_msr();
+
 	rapl_probe(family, model);
 	perf_limit_reasons_probe(family, model);
 
 	if (debug)
-		dump_cstate_pstate_config_info();
+		dump_cstate_pstate_config_info(family, model);
 
 	if (has_skl_msrs(family, model))
 		calculate_tsc_tweak();
 
+	do_gfx_rc6_ms = !access("/sys/class/drm/card0/power/rc6_residency_ms", R_OK);
+
+	do_gfx_mhz = !access("/sys/class/graphics/fb0/device/drm/card0/gt_cur_freq_mhz", R_OK);
+
 	return;
 }
 
 void help()
 {
-	fprintf(stderr,
+	fprintf(outf,
 	"Usage: turbostat [OPTIONS][(--interval seconds) | COMMAND ...]\n"
 	"\n"
 	"Turbostat forks the specified COMMAND and prints statistics\n"
@@ -2814,6 +3390,7 @@ void help()
 	"--help		print this help message\n"
 	"--counter msr	print 32-bit counter at address \"msr\"\n"
 	"--Counter msr	print 64-bit Counter at address \"msr\"\n"
+	"--out file	create or truncate \"file\" for all output\n"
 	"--msr msr	print 32-bit value at address \"msr\"\n"
 	"--MSR msr	print 64-bit Value at address \"msr\"\n"
 	"--version	print version information\n"
@@ -2858,7 +3435,7 @@ void topology_probe()
 		show_cpu = 1;
 
 	if (debug > 1)
-		fprintf(stderr, "num_cpus %d max_cpu_num %d\n", topo.num_cpus, topo.max_cpu_num);
+		fprintf(outf, "num_cpus %d max_cpu_num %d\n", topo.num_cpus, topo.max_cpu_num);
 
 	cpus = calloc(1, (topo.max_cpu_num  + 1) * sizeof(struct cpu_topology));
 	if (cpus == NULL)
@@ -2893,7 +3470,7 @@ void topology_probe()
 
 		if (cpu_is_not_present(i)) {
 			if (debug > 1)
-				fprintf(stderr, "cpu%d NOT PRESENT\n", i);
+				fprintf(outf, "cpu%d NOT PRESENT\n", i);
 			continue;
 		}
 		cpus[i].core_id = get_core_id(i);
@@ -2908,26 +3485,26 @@ void topology_probe()
 		if (siblings > max_siblings)
 			max_siblings = siblings;
 		if (debug > 1)
-			fprintf(stderr, "cpu %d pkg %d core %d\n",
+			fprintf(outf, "cpu %d pkg %d core %d\n",
 				i, cpus[i].physical_package_id, cpus[i].core_id);
 	}
 	topo.num_cores_per_pkg = max_core_id + 1;
 	if (debug > 1)
-		fprintf(stderr, "max_core_id %d, sizing for %d cores per package\n",
+		fprintf(outf, "max_core_id %d, sizing for %d cores per package\n",
 			max_core_id, topo.num_cores_per_pkg);
 	if (debug && !summary_only && topo.num_cores_per_pkg > 1)
 		show_core = 1;
 
 	topo.num_packages = max_package_id + 1;
 	if (debug > 1)
-		fprintf(stderr, "max_package_id %d, sizing for %d packages\n",
+		fprintf(outf, "max_package_id %d, sizing for %d packages\n",
 			max_package_id, topo.num_packages);
 	if (debug && !summary_only && topo.num_packages > 1)
 		show_pkg = 1;
 
 	topo.num_threads_per_core = max_siblings;
 	if (debug > 1)
-		fprintf(stderr, "max_siblings %d\n", max_siblings);
+		fprintf(outf, "max_siblings %d\n", max_siblings);
 
 	free(cpus);
 }
@@ -3019,10 +3596,27 @@ void allocate_output_buffer()
 	if (outp == NULL)
 		err(-1, "calloc output buffer");
 }
+void allocate_fd_percpu(void)
+{
+	fd_percpu = calloc(topo.max_cpu_num, sizeof(int));
+	if (fd_percpu == NULL)
+		err(-1, "calloc fd_percpu");
+}
+void allocate_irq_buffers(void)
+{
+	irq_column_2_cpu = calloc(topo.num_cpus, sizeof(int));
+	if (irq_column_2_cpu == NULL)
+		err(-1, "calloc %d", topo.num_cpus);
 
+	irqs_per_cpu = calloc(topo.max_cpu_num, sizeof(int));
+	if (irqs_per_cpu == NULL)
+		err(-1, "calloc %d", topo.max_cpu_num);
+}
 void setup_all_buffers(void)
 {
 	topology_probe();
+	allocate_irq_buffers();
+	allocate_fd_percpu();
 	allocate_counters(&thread_even, &core_even, &package_even);
 	allocate_counters(&thread_odd, &core_odd, &package_odd);
 	allocate_output_buffer();
@@ -3036,7 +3630,7 @@ void set_base_cpu(void)
 		err(-ENODEV, "No valid cpus found");
 
 	if (debug > 1)
-		fprintf(stderr, "base_cpu = %d\n", base_cpu);
+		fprintf(outf, "base_cpu = %d\n", base_cpu);
 }
 
 void turbostat_init()
@@ -3049,6 +3643,9 @@ void turbostat_init()
 
 
 	if (debug)
+		for_all_cpus(print_hwp, ODD_COUNTERS);
+
+	if (debug)
 		for_all_cpus(print_epb, ODD_COUNTERS);
 
 	if (debug)
@@ -3061,6 +3658,9 @@ void turbostat_init()
 
 	if (debug)
 		for_all_cpus(print_thermal, ODD_COUNTERS);
+
+	if (debug && do_irtl_snb)
+		print_irtl();
 }
 
 int fork_it(char **argv)
@@ -3100,9 +3700,10 @@ int fork_it(char **argv)
 	for_all_cpus_2(delta_cpu, ODD_COUNTERS, EVEN_COUNTERS);
 	compute_average(EVEN_COUNTERS);
 	format_all_counters(EVEN_COUNTERS);
-	flush_stderr();
 
-	fprintf(stderr, "%.6f sec\n", tv_delta.tv_sec + tv_delta.tv_usec/1000000.0);
+	fprintf(outf, "%.6f sec\n", tv_delta.tv_sec + tv_delta.tv_usec/1000000.0);
+
+	flush_output_stderr();
 
 	return status;
 }
@@ -3119,13 +3720,13 @@ int get_and_dump_counters(void)
 	if (status)
 		return status;
 
-	flush_stdout();
+	flush_output_stdout();
 
 	return status;
 }
 
 void print_version() {
-	fprintf(stderr, "turbostat version 4.8 26-Sep, 2015"
+	fprintf(outf, "turbostat version 4.12 5 Apr 2016"
 		" - Len Brown <lenb@kernel.org>\n");
 }
 
@@ -3143,6 +3744,7 @@ void cmdline(int argc, char **argv)
 		{"Joules",	no_argument,		0, 'J'},
 		{"MSR",		required_argument,	0, 'M'},
 		{"msr",		required_argument,	0, 'm'},
+		{"out",		required_argument,	0, 'o'},
 		{"Package",	no_argument,		0, 'p'},
 		{"processor",	no_argument,		0, 'p'},
 		{"Summary",	no_argument,		0, 'S'},
@@ -3153,7 +3755,7 @@ void cmdline(int argc, char **argv)
 
 	progname = argv[0];
 
-	while ((opt = getopt_long_only(argc, argv, "+C:c:Ddhi:JM:m:PpST:v",
+	while ((opt = getopt_long_only(argc, argv, "+C:c:Ddhi:JM:m:o:PpST:v",
 				long_options, &option_index)) != -1) {
 		switch (opt) {
 		case 'C':
@@ -3173,7 +3775,18 @@ void cmdline(int argc, char **argv)
 			help();
 			exit(1);
 		case 'i':
-			interval_sec = atoi(optarg);
+			{
+				double interval = strtod(optarg, NULL);
+
+				if (interval < 0.001) {
+					fprintf(outf, "interval %f seconds is too small\n",
+						interval);
+					exit(2);
+				}
+
+				interval_ts.tv_sec = interval;
+				interval_ts.tv_nsec = (interval - interval_ts.tv_sec) * 1000000000;
+			}
 			break;
 		case 'J':
 			rapl_joules++;
@@ -3184,6 +3797,9 @@ void cmdline(int argc, char **argv)
 		case 'm':
 			sscanf(optarg, "%x", &extra_msr_offset32);
 			break;
+		case 'o':
+			outf = fopen_or_die(optarg, "w");
+			break;
 		case 'P':
 			show_pkg_only++;
 			break;
@@ -3206,6 +3822,8 @@ void cmdline(int argc, char **argv)
 
 int main(int argc, char **argv)
 {
+	outf = stderr;
+
 	cmdline(argc, argv);
 
 	if (debug)