On Tue, May 20, 2014 at 02:39:27PM -0700, Tim Chen wrote:
> From: Tim Chen <tim.c.chen@linux.intel.com>
> Subject: [PATCH v2] sched: Reduce the rate of needless idle load balancing
> 
> 
> The current no_hz idle load balancer do load balancing for *all* idle cpus,
> even though the time due to load balance for a particular
> idle cpu could be still a while in the future.  This introduces a much
> higher load balancing rate than what is necessary.  The patch
> changes the behavior by only doing idle load balancing on
> behalf of an idle cpu only when it is due for load balancing.
> 
> On SGI's systems with over 3000 cores, the cpu responsible for idle balancing
> got overwhelmed with idle balancing, and introduces a lot of OS noise
> to workloads.  This patch fixes the issue.
> 
> Acked-by: Russ Anderson <rja@sgi.com>
> Reviewed-by: Rik van Riel <riel@redhat.com>
> Reviewed-by: Jason Low <jason.low2@hp.com>
> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
> ---

Thanks!