[PATCH] mm, vmstat: make quiet_vmstat lighter (was: Re: fast path cycle muncher (vmstat: make vmstat_updater deferrable) again and shut down on idle)

[Michal Hocko]

On Sat 23-01-16 17:21:55, Mike Galbraith wrote:
> Hi Christoph,
> 
> While you're fixing that commit up, can you perhaps find a better home
> for quiet_vmstat()?  It not only munches cycles when switching cross
> -core mightily, for -rt it injects a sleeping lock into the idle task.
> 
>     12.89%  [kernel]       [k] refresh_cpu_vm_stats.isra.12
>      4.75%  [kernel]       [k] __schedule                  
>      4.70%  [kernel]       [k] mutex_unlock                
>      3.14%  [kernel]       [k] __switch_to                 

What about the following fix?
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