Spinlocks are normal userspace code issuing machine instructions in a loop that do memory operations. It is counted in user time, unless the platform is unusual

Spinlocks are normal userspace code issuing machine instructions in a loop that do memory operations. It is counted in user time, unless the platform is unusual and for some reason enters the kernel to spin on the lock. Spinning is the opposite of sleeping. edit: misparsed, like corrected below, my bad.