On Tue, Nov 11, 2014 at 07:02:48PM +0800, Huacai Chen wrote: > Loops_per_jiffy is set on startup and doesn't change later. It reflect > the maximum value frequency, but for CPU hotplug, a new online CPU may > not run at the maximum frequency (remain the old value before it is > offline). As suspected. But what if a CPU is hotunplugged, then the clockrate for all the CPUs changes and then the gets re-hotplugged into the system. Wouldn't in that case the udelay_val be used? Ralf
