Re: [tip:sched/core] sched/isolation: Document the isolcpus= flags

[Christopher Lameter]

On Fri, 27 Oct 2017, Peter Zijlstra wrote:

> I _strongly_ object to this statement, isolcpus is _not_ the preferred
> way, cpusets are.
>
> And yes, while cpusets suffers some problems, we _should_ really fix
> those and not promote this piece of shit isolcpus crap.

Well low level control at the processor level is important and this allows
controlling activities on a processor that is supposed to be dedicated to
certain activities without OS interaction.

isolcpus is the *right* approach here because you are micromanaging the OS
and are putting dedicated pieces of software on each core.

A cgroup suggests that threads would be scheduled over multiple cores
which is *not* what you want. cgroup has to do something with containers
etc which is inherently more noisy and needed if you want to do different
things with your processing resources.