Re: [PATCH 9/7] sched,numa: remove task_h_load from task_numa_compare

[Peter Zijlstra]

On Wed, Jun 25, 2014 at 01:25:00AM -0400, Rik van Riel wrote:
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> On 06/25/2014 01:21 AM, Peter Zijlstra wrote:
> > On Wed, Jun 25, 2014 at 07:07:35AM +0200, Peter Zijlstra wrote:
> >> Shall I merge this into patch 3?
> > 
> > Which gets me the below; which is has a wrong changelog.
> > 
> > task_h_load() already computes the load as seen from the root
> > group. effective_load() just does a better (and more expensive) job
> > of computing the task movement implications of a move.
> > 
> > So the total effect of this patch shouldn't be very big; regular
> > load balancing also only uses task_h_load(), see move_tasks().
> > 
> > Now, we don't run with preemption disabled, don't run as often,
> > etc.., so maybe we can indeed use the more expensive variant just
> > fine, but does it really matter?
> 
> In my testing, it appears to make a difference between workloads
> converging, and workloads sitting with one last thread stuck on
> another node that never gets moved...

Fair enough; can you provide a new Changelog that I can paste in?

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