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

Rafael J. Wysocki
2025-09-11T09:42:38Z

+Srinivas & Rui

On Thu, Sep 11, 2025 at 2:20 AM Kenneth Crudup <kenny@panix.com> wrote:
>
> 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
>
>