4 ms·Kernel code, user-space code is always preemptible.by GrayShade 2y agoKernel code, user-space code is always preemptible.fguerraz 2y agoNot true when the user-space thread has RT priority.temac 2y agoRT threads can be prempted by higher prio RT, and IIRC some kernel threads run at the highest prio. Plus you can be prempted by SMI, an hypervisor, etc