pcm-memory can not read socket 0 in dual socket

[baonq-me]

Memory channel 0 in socket 0 return -1 value on dual Xeon 6150 system, Dell R740xd. I use pcm at latest build 202502

 Intel(r) Performance Counter Monitor: Memory Bandwidth Monitoring Utility (2025-02-25 10:03:48 +0100 ID=5cb70ffd)

 This utility measures memory bandwidth per channel or per DIMM rank in real-time


=====  Processor information  =====
Linux arch_perfmon flag  : yes
Hybrid processor         : no
IBRS and IBPB supported  : yes
STIBP supported          : yes
Spec arch caps supported : yes
Max CPUID level          : 22
CPU family               : 6
CPU model number         : 85
Number of physical cores: 36
Number of logical cores: 72
Number of online logical cores: 72
Threads (logical cores) per physical core: 2
Num sockets: 2
Physical cores per socket: 18
Last level cache slices per socket: 18
Core PMU (perfmon) version: 4
Number of core PMU generic (programmable) counters: 3
Width of generic (programmable) counters: 48 bits
Number of core PMU fixed counters: 3
Width of fixed counters: 48 bits
Nominal core frequency: 2700000000 Hz
IBRS enabled in the kernel   : yes
STIBP enabled in the kernel  : no
The processor is not susceptible to Rogue Data Cache Load: no
The processor supports enhanced IBRS                     : no
Package thermal spec power: 165 Watt; Package minimum power: 80 Watt; Package maximum power: 363 Watt;

INFO: Linux perf interface to program uncore PMUs is present
Socket 0: 2 memory controllers detected with total number of 6 channels. 3 UPI ports detected. 2 M2M (mesh to memory)/B2CMI blocks detected. 0 HBM M2M blocks detected. 0 EDC/HBM channels detected. 0 Home Agents detected. 3 M3UPI/B2UPI blocks detected.
Socket 1: 2 memory controllers detected with total number of 6 channels. 3 UPI ports detected. 2 M2M (mesh to memory)/B2CMI blocks detected. 0 HBM M2M blocks detected. 0 EDC/HBM channels detected. 0 Home Agents detected. 3 M3UPI/B2UPI blocks detected.
Socket 0: 1 PCU units detected. 6 IIO units detected. 6 IRP units detected. 18 CHA/CBO units detected. 0 MDF units detected. 1 UBOX units detected. 0 CXL units detected. 0 PCIE_GEN5x16 units detected. 0 PCIE_GEN5x8 units detected.
Socket 1: 1 PCU units detected. 6 IIO units detected. 6 IRP units detected. 18 CHA/CBO units detected. 0 MDF units detected. 1 UBOX units detected. 0 CXL units detected. 0 PCIE_GEN5x16 units detected. 0 PCIE_GEN5x8 units detected.
Initializing RMIDs


Detected Intel(R) Xeon(R) Gold 6150 CPU @ 2.70GHz "Intel(r) microarchitecture codename Skylake-SP" stepping 4 microcode level 0x2007006
Update every 1 seconds
|---------------------------------------||---------------------------------------|
|--             Socket  0             --||--             Socket  1             --|
|---------------------------------------||---------------------------------------|
|--     Memory Channel Monitoring     --||--     Memory Channel Monitoring     --|
|---------------------------------------||---------------------------------------|
|-- Mem Ch  0: Reads (MB/s):    -1.00 --||-- Mem Ch  0: Reads (MB/s):   288.82 --|
|--            Writes(MB/s):    -1.00 --||--            Writes(MB/s):   523.69 --|
|-- SKT  0 Mem Read (MB/s) :     0.00 --||-- SKT  1 Mem Read (MB/s) :   288.82 --|
|-- SKT  0 Mem Write(MB/s) :     0.00 --||-- SKT  1 Mem Write(MB/s) :   523.69 --|
|-- SKT  0 P. Write (T/s):          0 --||-- SKT  1 P. Write (T/s):       6289 --|
|-- SKT  0 Memory (MB/s):        0.00 --||-- SKT  1 Memory (MB/s):      812.52 --|
|---------------------------------------||---------------------------------------|
|---------------------------------------||---------------------------------------|
|--                 System Read Throughput(MB/s):        288.82                --|
|--                System Write Throughput(MB/s):        523.69                --|
|--               System Memory Throughput(MB/s):        812.52                --|
|---------------------------------------||---------------------------------------|
^CDEBUG: caught signal to interrupt (Interrupt).
Cleaning up
 Closed perf event handles
 Zeroed uncore PMU registers
 Freeing up all RMIDs
root@curiosity:/opt/pcm-202502/build/bin#

[baonq-me]

I tested again on another system with the same dual Xeon 6150 (HP DL380 G10) at build commit 66121f83b1fe6c7d49db3acc1b41e0ab8fcc9625, still showing all memory channel value in both sockets

root@explorer:/opt/pcm/build/bin# ./pcm-memory

 Intel(r) Performance Counter Monitor: Memory Bandwidth Monitoring Utility ($Format:%ci ID=%h$)

 This utility measures memory bandwidth per channel or per DIMM rank in real-time


=====  Processor information  =====
Linux arch_perfmon flag  : yes
Hybrid processor         : no
IBRS and IBPB supported  : yes
STIBP supported          : yes
Spec arch caps supported : yes
Max CPUID level          : 22
CPU model number         : 85
Number of physical cores: 36
Number of logical cores: 72
Number of online logical cores: 72
Threads (logical cores) per physical core: 2
Num sockets: 2
Physical cores per socket: 18
Last level cache slices per socket: 18
Core PMU (perfmon) version: 4
Number of core PMU generic (programmable) counters: 3
Width of generic (programmable) counters: 48 bits
Number of core PMU fixed counters: 3
Width of fixed counters: 48 bits
Nominal core frequency: 2700000000 Hz
IBRS enabled in the kernel   : yes
STIBP enabled in the kernel  : no
The processor is not susceptible to Rogue Data Cache Load: no
The processor supports enhanced IBRS                     : no
Package thermal spec power: 165 Watt; Package minimum power: 80 Watt; Package maximum power: 363 Watt;

INFO: Linux perf interface to program uncore PMUs is present
Socket 0: 2 memory controllers detected with total number of 6 channels. 3 UPI ports detected. 2 M2M (mesh to memory)/B2CMI blocks detected. 0 HBM M2M blocks detected. 0 EDC/HBM channels detected. 0 Home Agents detected. 3 M3UPI/B2UPI blocks detected.
Socket 1: 2 memory controllers detected with total number of 6 channels. 3 UPI ports detected. 2 M2M (mesh to memory)/B2CMI blocks detected. 0 HBM M2M blocks detected. 0 EDC/HBM channels detected. 0 Home Agents detected. 3 M3UPI/B2UPI blocks detected.
Socket 0: 1 PCU units detected. 6 IIO units detected. 6 IRP units detected. 18 CHA/CBO units detected. 0 MDF units detected. 1 UBOX units detected. 0 CXL units detected. 0 PCIE_GEN5x16 units detected. 0 PCIE_GEN5x8 units detected.
Socket 1: 1 PCU units detected. 6 IIO units detected. 6 IRP units detected. 18 CHA/CBO units detected. 0 MDF units detected. 1 UBOX units detected. 0 CXL units detected. 0 PCIE_GEN5x16 units detected. 0 PCIE_GEN5x8 units detected.
Initializing RMIDs


Detected Intel(R) Xeon(R) Gold 6150 CPU @ 2.70GHz "Intel(r) microarchitecture codename Skylake-SP" stepping 4 microcode level 0x2007108
Update every 1 seconds
|---------------------------------------||---------------------------------------|
|--             Socket  0             --||--             Socket  1             --|
|---------------------------------------||---------------------------------------|
|--     Memory Channel Monitoring     --||--     Memory Channel Monitoring     --|
|---------------------------------------||---------------------------------------|
|-- Mem Ch  0: Reads (MB/s):    27.73 --||-- Mem Ch  0: Reads (MB/s):   163.08 --|
|--            Writes(MB/s):    19.78 --||--            Writes(MB/s):    45.15 --|
|-- Mem Ch  1: Reads (MB/s):    28.21 --||-- Mem Ch  1: Reads (MB/s):   168.21 --|
|--            Writes(MB/s):    20.31 --||--            Writes(MB/s):    47.97 --|
|-- Mem Ch  2: Reads (MB/s):    27.89 --||-- Mem Ch  2: Reads (MB/s):   163.13 --|
|--            Writes(MB/s):    20.16 --||--            Writes(MB/s):    45.30 --|
|-- Mem Ch  3: Reads (MB/s):    23.27 --||-- Mem Ch  3: Reads (MB/s):   125.64 --|
|--            Writes(MB/s):    18.12 --||--            Writes(MB/s):    43.48 --|
|-- Mem Ch  4: Reads (MB/s):    22.52 --||-- Mem Ch  4: Reads (MB/s):   124.69 --|
|--            Writes(MB/s):    17.25 --||--            Writes(MB/s):    42.43 --|
|-- Mem Ch  5: Reads (MB/s):    22.47 --||-- Mem Ch  5: Reads (MB/s):   124.96 --|
|--            Writes(MB/s):    17.25 --||--            Writes(MB/s):    42.54 --|
|-- NODE 0 Mem Read (MB/s) :   152.09 --||-- NODE 1 Mem Read (MB/s) :   869.71 --|
|-- NODE 0 Mem Write(MB/s) :   112.87 --||-- NODE 1 Mem Write(MB/s) :   266.87 --|
|-- NODE 0 P. Write (T/s):      76251 --||-- NODE 1 P. Write (T/s):      38135 --|
|-- NODE 0 Memory (MB/s):      264.97 --||-- NODE 1 Memory (MB/s):     1136.57 --|
|---------------------------------------||---------------------------------------|
|---------------------------------------||---------------------------------------|
|--                 System Read Throughput(MB/s):       1021.80                --|
|--                System Write Throughput(MB/s):        379.74                --|
|--               System Memory Throughput(MB/s):       1401.54                --|
|---------------------------------------||---------------------------------------|
^CDEBUG: caught signal to interrupt (Interrupt).
Cleaning up
 Closed perf event handles
 Zeroed uncore PMU registers
 Freeing up all RMIDs

[rdementi]

Hi, could you please share the "dmidecode -t memory" output from your first system where PCM shows no populated channels in socket 0?