Messages in this thread | | | Date | Thu, 15 Aug 2013 19:39:53 +0200 | From | Peter Zijlstra <> | Subject | Re: false nr_running check in load balance? |
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On Tue, Aug 13, 2013 at 01:08:17AM -0700, Paul Turner wrote: > On Tue, Aug 13, 2013 at 12:38 AM, Peter Zijlstra <peterz@infradead.org> wrote: > > On Tue, Aug 13, 2013 at 12:45:12PM +0800, Lei Wen wrote: > >> > Not quite right; I think you need busiest->cfs.h_nr_running. > >> > cfs.nr_running is the number of entries running in this 'group'. If > >> > you've got nested groups like: > >> > > >> > 'root' > >> > \ > >> > 'A' > >> > / \ > >> > t1 t2 > >> > > >> > root.nr_running := 1 'A', even though you've got multiple running tasks.
One thing though; doesn't h_nr_running over count the number of tasks? That is, doesn't it count the runnable entities so the above case would give root.h_nr_running := 3, where we would only have 2 runnable tasks.
Double check this and be careful when doing the conversion.
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