System Monitor shows 5 CPU's on Raspberry pi ARM Quad Core system

[Koenraad Koster]

The System Monitor application on Ubuntu Mate for Raspberry Pi shows 5 CPU's on a Quad Core ARM CPU.

[Jaime Carpenter (j.carpenter)]

I also have this issue. I do not see it as a duplicate of bug #1615846 because this is an ARM processor. While the behavior is the same, I am running on different hardware. I have a new Raspberry Pi 3 A+ running Raspbian (Debian based) and I have the same issue with gnome-system-monitor.

I have found other thread that speak of an issue with parsing the output of /proc/cpuinfo. Seems that the non-processor paragraph at the end is picked up as another processor in the count.

Here is the output of /proc/cpuinfo:

$ cat /proc/cpuinfo
processor : 0
model name : ARMv7 Processor rev 4 (v7l)
BogoMIPS : 89.60
Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xd03
CPU revision : 4

processor : 1
model name : ARMv7 Processor rev 4 (v7l)
BogoMIPS : 89.60
Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xd03
CPU revision : 4

processor : 2
model name : ARMv7 Processor rev 4 (v7l)
BogoMIPS : 89.60
Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xd03
CPU revision : 4

processor : 3
model name : ARMv7 Processor rev 4 (v7l)
BogoMIPS : 89.60
Features : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xd03
CPU revision : 4

Hardware : BCM2835
Revision : 9020e0
Serial : 00000000a38faca4

Here is the output of lscpu:
$ lscpu
Architecture: armv7l
Byte Order: Little Endian
CPU(s): 4
On-line CPU(s) list: 0-3
Thread(s) per core: 1
Core(s) per socket: 4
Socket(s): 1
Model: 4
Model name: ARMv7 Processor rev 4 (v7l)
CPU max MHz: 1400.0000
CPU min MHz: 600.0000
BogoMIPS: 89.60
Flags: half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32

gnome-system-monitor 3.22.2 shows 5 cpus and the 5th one has no data.