On 22 December 2017 at 08:56, Peter Zijlstra <[email protected]> wrote: > On Thu, Dec 21, 2017 at 05:23:27PM +0100, Vincent Guittot wrote: >> Hi Peter, >> >> I think that part of the proposal is missing. >> >> One goal of the patchset was to kick an update of the stats of idle >> cpu when a task wake up on a cpu but the statistic has not been >> updated for a while. >> >> That's why there where a call to nohz_kick_needed in the proposal to >> kick ilb but only for updating blocked load and not a full idle load >> balance >> >> I can't find this call any more in your patchset > > Yeah, I took it out because it didn't make sense to me. If you're waking > to a stale CPU, you're too late.
I agree that's it's too late for the current wake up but that's the trade off with delaying the wake up until all blocked load has been updated. >
