Re: [PATCH 08/10] psi: pressure stall information for CPU, memory, and IO

From: Johannes Weiner
Date: Wed Jul 18 2018 - 18:08:56 EST


On Tue, Jul 17, 2018 at 05:17:05PM +0200, Peter Zijlstra wrote:
> On Thu, Jul 12, 2018 at 01:29:40PM -0400, Johannes Weiner wrote:
> > @@ -457,6 +457,22 @@ config TASK_IO_ACCOUNTING
> >
> > Say N if unsure.
> >
> > +config PSI
> > + bool "Pressure stall information tracking"
> > + select SCHED_INFO
>
> What's the deal here? AFAICT it does not in fact use SCHED_INFO for
> _anything_. You just hooked into the sched_info_{en,de}queue() hooks,
> but you don't use any of the sched_info data.
>
> So the dependency is an artificial one that should not exist.

You're right, it doesn't strictly depend on it. I'll split that out.