Sometimes I only see 3 RAPL (out of 4) Counters

Kenneth Crudup
2025-09-11T00:20:22Z

I have a Dell XPS-9320, with a i7-1280P (family: 0x6, model: 0x9a,
stepping: 0x3) CPU. Sometimes I'll only see 3 RAPL counters instead of
the normal 4. (It used to happen a lot more often, BTW):

----
gunzip --force --stdout /var/log/syslog* | fgrep -i rapl | fgrep fixed
2025-09-08T12:09:05.915989-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 3 fixed counters, 655360 ms ovfl timer
2025-09-09T08:52:19.098522-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-09-09T17:25:24.377784-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-09-09T17:50:09.334140-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-09-10T16:42:13.259270-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 3 fixed counters, 655360 ms ovfl timer
2025-09-10T16:46:36.322016-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-09-02T13:05:02.632218-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-09-02T14:07:19.683466-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-09-02T14:20:43.602483-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-09-04T13:13:38.636326-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-09-05T09:21:50.147180-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-08-29T10:57:14.419740-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-08-17T11:52:55.733943-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-08-19T07:52:30.696326-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-08-19T07:55:49.083600-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-08-20T10:53:54.601680-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-08-20T11:00:09.560496-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
2025-08-20T11:12:30.580414-07:00 xps-9320 kernel: [ T1] RAPL PMU: API
unit is 2^-32 Joules, 4 fixed counters, 655360 ms ovfl timer
----

... and it's always(?) the GPU RAPL:

----
gunzip --force --stdout /var/log/syslog* | fgrep -i rapl | cut -d\] -f2-
| sort -f | uniq -c
grep: (standard input): binary file matches
18 intel_rapl_common: Found RAPL domain core
36 intel_rapl_common: Found RAPL domain package
18 intel_rapl_common: Found RAPL domain psys
16 intel_rapl_common: Found RAPL domain uncore
18 intel_rapl_msr: PL4 support detected.
2 RAPL PMU: API unit is 2^-32 Joules, 3 fixed counters, 655360
ms ovfl timer
16 RAPL PMU: API unit is 2^-32 Joules, 4 fixed counters, 655360
ms ovfl timer
18 RAPL PMU: hw unit of domain package 2^-14 Joules
18 RAPL PMU: hw unit of domain pp0-core 2^-14 Joules
16 RAPL PMU: hw unit of domain pp1-gpu 2^-14 Joules
18 RAPL PMU: hw unit of domain psys 2^-14 Joules
----

A reboot fixes it up again (and that's if I even notice), but what would
cause this to happen? What's the effect of it missing the RAPL counter, BTW?

LMK if you need more info,

-Kenny

--
Kenneth R. Crudup / Sr. SW Engineer, Scott County Consulting, Orange
County CA