Booting kernel without SMP support

We have a program which opens a lot of threads make some time critical calculations. I wonder about SMP scheduling effect. It is possible to boot Linux kernel with nosmp or maxcpus=0 argument to disable multiple processing support. But is there any way to make this without rebooting the system?

It is possible to set a CPU to offline or online mode through sysfs while system running.

You can set online variable to 0 for each of the cpu cores which you want to make offline:

echo 0 > /sys/devices/system/cpu/cpu2/online

Think about what will be happen if you set all of the cpu cores to offline :wink: