Messages in this thread | | | Date | Thu, 24 Apr 2014 19:29:33 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 1/3] sched, balancing: Update rq->max_idle_balance_cost whenever newidle balance is attempted |
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On Thu, Apr 24, 2014 at 07:14:53PM +0200, Peter Zijlstra wrote: > On Thu, Apr 24, 2014 at 09:53:37AM -0700, Jason Low wrote: > > > > So I thought that the original rationale (commit 1bd77f2d) behind > > updating rq->next_balance in idle_balance() is that, if we are going > > idle (!pulled_task), we want to ensure that the next_balance gets > > calculated without the busy_factor. > > > > If the rq is busy, then rq->next_balance gets updated based on > > sd->interval * busy_factor. However, when the rq goes from "busy" > > to idle, rq->next_balance might still have been calculated under > > the assumption that the rq is busy. Thus, if we are going idle, we > > would then properly update next_balance without the busy factor > > if we update when !pulled_task. > > > > Its late here and I'm confused! > > So the for_each_domain() loop calculates a new next_balance based on > ->balance_interval (which has that busy_factor on, right).
Not right, ->balance_interval is the base interval. rebalance_domains() doesn't update it.
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