Approved version. Approved on: 15:25, 23 June 2022
- Last edited 11 months ago ago
How to disable one CPU
This article is only applicable for STMP32 Microprocessor with more than one CPU.
1 How to see the number of active CPU[edit]
root@st:~# cat /proc/cpuinfo processor : 0 model name : ARMv7 Processor rev 0 (v7l) BogoMIPS : 2387.14 Features : swp half thumb fastmult vfp edsp neon vfpv3 tls CPU implementer : 0x41 CPU architecture: 7 CPU variant : 0x3 CPU part : 0xc09 CPU revision : 0 processor : 1 model name : ARMv7 Processor rev 0 (v7l) BogoMIPS : 2393.70 Features : swp half thumb fastmult vfp edsp neon vfpv3 tls CPU implementer : 0x41 CPU architecture: 7 CPU variant : 0x3 CPU part : 0xc09 CPU revision : 0 Hardware : STi SoC with Flattened Device Tree Revision : 0000 Serial : 0000000000000000
2 How to disable a CPU[edit]
On this example we disable CPU1
root@st:~# echo 0 > /sys/devices/system/cpu/cpu1/online CPU1: shutdown root@st:~# cat /proc/cpuinfo processor : 0 model name : ARMv7 Processor rev 0 (v7l) BogoMIPS : 2387.14 Features : swp half thumb fastmult vfp edsp neon vfpv3 tls CPU implementer : 0x41 CPU architecture: 7 CPU variant : 0x3 CPU part : 0xc09 CPU revision : 0 Hardware : STi SoC with Flattened Device Tree Revision : 0000 Serial : 0000000000000000
3 How to enable a disabled CPU[edit]
On this example we enable CPU1
root@st:~# echo 1 > /sys/devices/system/cpu/cpu1/online CPU1: shutdown