ess() after some debugging it turns out that commit ca1b940c accidentally left interrupts disabled - which trickled down all the way to the first time we fork a kernel thread and triggered the warning. the fix is to re-enable interrupts in the 'else' branch of setup_boot_APIC_clock()'s pmtimers calibration path. Reported-by: Michal Piotrowski Signed-off-by: Ingo Molnar Acked-by: Thomas Gleixner Signed-off-by: Linus Torvalds D1Gx