Re: [GIT pull] x86/cache: Updates for 4.10

From: Peter Zijlstra
Date: Tue Dec 13 2016 - 03:04:35 EST


On Mon, Dec 12, 2016 at 08:26:50PM -0800, Linus Torvalds wrote:
> On Mon, Dec 12, 2016 at 1:53 AM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> >
> > This update provides the support for Intel Cache Allocation Technology, a
> > cache partitioning mechanism.
>
> Ugh, this is some funky stuff. And it's entirely x86-specific, with a
> rather odd special filesystem interface.
>
> It looks pretty self-contained (good), but it also looks majorly
> strange. I will have to think about this. What are the main/expected
> users?

>From what I know its aimed at two groups of users:

Firstly the Virtual Machine usecase, where, by assigning cache masks to
individual VMs you avoid one highly active VM trashing the cache of
another.

Secondly the Real-Time usecase, where we can assign cache slices to
individual CPUs such that we can better isolate RT and !RT workloads
running on the same cache domain (socket).