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Message-ID: <1361367264.10155.31.camel@laptop>
Subject: Re: [patch v5 06/15] sched: log the cpu utilization at rq
From: Peter Zijlstra <peterz@infradead.org>
To: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Alex Shi <alex.shi@intel.com>, torvalds@linux-foundation.org,
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Date: Wed, 20 Feb 2013 14:34:24 +0100
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On Wed, 2013-02-20 at 17:39 +0530, Preeti U Murthy wrote:
> Hi,
> 
> >>  /*
> >>   * This is the main, per-CPU runqueue data structure.
> >>   *
> >> @@ -481,6 +484,7 @@ struct rq {
> >>  #endif
> >>  
> >>  	struct sched_avg avg;
> >> +	unsigned int util;
> >>  };
> >>  
> >>  static inline int cpu_of(struct rq *rq)
> > 
> > You don't actually compute the rq utilization, you only compute the
> > utilization as per the fair class, so if there's significant RT activity
> > it'll think the cpu is under-utilized, whihc I think will result in the
> > wrong thing.
> 
> Correct me if I am wrong,but isn't the current load balancer also
> disregarding the real time tasks to calculate the domain/group/cpu level
> load too?

Nope, the rt utilization affects the cpu_power, thereby correcting the
weight stuff.