tools/power turbostat: report CoreThr per measurement interval

The CoreThr column displays total thermal throttling events
since boot time.

Change it to report events during the measurement interval.

This is more useful for showing a user the current conditions.
Total events since boot time are still available to the user via
/sys/devices/system/cpu/cpu*/thermal_throttle/*

Document CoreThr on turbostat.8

Fixes: eae97e0 ("turbostat: Support thermal throttle count print")
Reported-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: Chen Yu <yu.c.chen@intel.com>

tools/power/x86/turbostat/turbostat.8

@@ -172,6 +172,8 @@ The system configuration dump (if --quiet is not used) is followed by statistics
 .PP
 \fBPkgTmp\fP Degrees Celsius reported by the per-package Package Thermal Monitor.
 .PP
+\fBCoreThr\fP Core Thermal Throttling events during the measurement interval.  Note that events since boot can be find in /sys/devices/system/cpu/cpu*/thermal_throttle/*
+.PP
 \fBGFX%rc6\fP The percentage of time the GPU is in the "render C6" state, rc6, during the measurement interval. From /sys/class/drm/card0/power/rc6_residency_ms or /sys/class/drm/card0/gt/gt0/rc6_residency_ms or /sys/class/drm/card0/device/tile0/gtN/gtidle/idle_residency_ms depending on the graphics driver being used.
 .PP
 \fBGFXMHz\fP Instantaneous snapshot of what sysfs presents at the end of the measurement interval. From /sys/class/graphics/fb0/device/drm/card0/gt_cur_freq_mhz or /sys/class/drm/card0/gt_cur_freq_mhz or /sys/class/drm/card0/gt/gt0/rps_cur_freq_mhz or /sys/class/drm/card0/device/tile0/gtN/freq0/cur_freq depending on the graphics driver being used.

tools/power/x86/turbostat/turbostat.c

@@ -3485,7 +3485,7 @@ void delta_core(struct core_data *new, struct core_data *old)
 	old->c6 = new->c6 - old->c6;
 	old->c7 = new->c7 - old->c7;
 	old->core_temp_c = new->core_temp_c;
-	old->core_throt_cnt = new->core_throt_cnt;
+	old->core_throt_cnt = new->core_throt_cnt - old->core_throt_cnt;
 	old->mc6_us = new->mc6_us - old->mc6_us;
 
 	DELTA_WRAP32(new->core_energy.raw_value, old->core_energy.raw_value);