Re: vmstat kthreads

["Paul E. McKenney" <paulmck@linux.vnet.ibm.com>]

On Tue, Jun 18, 2013 at 05:46:50PM +0000, Christoph Lameter wrote:
> On Tue, 18 Jun 2013, Paul E. McKenney wrote:
> 
> > I have been digging around the vmstat kthreads a bit, and it appears to
> > me that there is no reason to run a given CPU's vmstat kthread unless
> > that CPU spends some time executing in the kernel.  If correct, this
> > observation indicates that one way to safely reduce OS jitter due to the
> > vmstat kthreads is to prevent them from executing on a given CPU if that
> > CPU has been executing in usermode since the last time that this CPU's
> > vmstat kthread executed.
> 
> Right and we have patches to that effect.

Even better!

> > Does this seem like a sensible course of action, or did I miss something
> > when I went through the code?
> 
> Nope you are right on.
> 
> Gilad Ben-Yossef has been posting patches that address this issue in Feb
> 2012. Ccing him. Can we see your latest work, Gilead?

Is it this one?

https://lkml.org/lkml/2012/5/3/269

							Thanx, Paul

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