Re: vmstat: make vmstat_updater deferrable again and shut down on idle

From: Shiraz Hashim
Date: Wed Jan 20 2016 - 08:52:37 EST

Hi Christoph,

On Fri, Dec 11, 2015 at 2:15 AM, Christoph Lameter <cl@xxxxxxxxx> wrote:
> Currently the vmstat updater is not deferrable as a result of commit
> ba4877b9ca51f80b5d30f304a46762f0509e1635. This in turn can cause multiple
> interruptions of the applications because the vmstat updater may run at
> different times than tick processing. No good.
> Make vmstate_update deferrable again and provide a function that
> folds the differentials when the processor is going to idle mode thus
> addressing the issue of the above commit in a clean way.

The patch makes vmstat_shepherd deferable which if is quiesed
would not schedule vmstat update on other cpus. Wouldn't this
aggravate the problem of vmstat for rest cpus not gettng updated.