Configure grub.cfg for two CPU cores

Intel Yocto Linux

• modify grub.cfg for two cpu cores ...

GRUBCFG=/boot/efi/EFI/BOOT/grub.cfg
# backup original grub.cfg if not backup before
[[ ! -f $GRUBCFG.bak ]] && cp -a $GRUBCFG{,.bak} 

# display current setting
grep --color -E '(isolcpus|rcu_nocbs)=\S*' $GRUBCFG

# change isolcpus=* rcu_nocbs=* to change isolcpus=1-2 rcu_nocbs=1-2
sed -i "s/isolcpus=\S*/isolcpus=1-2/; s/rcu_nocbs=\S*/rcu_nocbs=1-2/" $GRUBCFG

# verification
grep --color -E '(isolcpus|rcu_nocbs)=\S*' $GRUBCFG

# if the grub.cfg is correct, reboot machine
reboot

• recover to the original grub.cfg ...

GRUBCFG=/boot/efi/EFI/BOOT/grub.cfg

# display current setting
grep --color -E '(isolcpus|rcu_nocbs)=\S*' $GRUBCFG

# recover
[[ -f $GRUBCFG.bak ]] && cp -a $GRUBCFG.bak $GRUBCFG

# verification
grep --color -E '(isolcpus|rcu_nocbs)=\S*' $GRUBCFG

# if the grub.cfg is recovered, reboot machine
reboot