On Mon 2022-04-25 15:27 +0200, Peter Zijlstra wrote: > On Mon, Apr 25, 2022 at 02:09:06PM +0200, Christoph Lameter wrote: > > 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. > > I'm thinking you're going to find a ton of regressions if you try it > though; some workloads go idle *very* shortly, doing all this accounting > is going to be counter-productive. Hi Peter, Christoph, Indeed. Which was why I decided, initially, against the general-purpose case/or approach. Personally, I would prefer to keep this somewhat restrictive to nohz. Kind regards, -- Aaron Tomlin
