On Mon, 25 Apr 2022, Aaron Tomlin wrote: > Yes, in the context of nohz, this patch should ensure it, if required, when > the idle tick is to be stopped. What I said was that it is generally useful. Even in the non NOHZ case. Folding the vmstat diffs *always* when entering idle prevents unnecessary wakeups and processing in the future and also provides more accurate counters for the VM allowing better decision to be made on reclaim.
