Messages in this thread | | | From | Paul Turner <> | Date | Fri, 17 Feb 2012 03:39:22 -0800 | Subject | Re: [RFC PATCH 05/14] sched: account for blocked load waking back up |
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On Thu, Feb 16, 2012 at 8:02 AM, Peter Zijlstra <a.p.zijlstra@chello.nl> wrote: > On Wed, 2012-02-01 at 17:38 -0800, Paul Turner wrote: > >> u64 last_runnable_update, decay_count; > >> + /* we track migrations using entity decay_count == 0 */ >> + if (unlikely(se->avg.decay_count <= 0)) { > > !sleep dequeue isn't migrate only,
Well they mostly are these days; but in the == 0 case we're either a load-balancer migration or someone doing a dequeue/enqueue pair on an entity about some sort of update.
The key is that when it is an load-balancer move we'll resync appropriately on enqueue (which we need to do). We will essentially sync with ourselves in the other cases, but they have no bearing on why we do this.
> also, <= 0 on an unsigned is weird.
Yeah that should be a s64 not u64 (fixed).
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