Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753502AbcLMIEU (ORCPT ); Tue, 13 Dec 2016 03:04:20 -0500 Received: from merlin.infradead.org ([205.233.59.134]:37366 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752863AbcLMIET (ORCPT ); Tue, 13 Dec 2016 03:04:19 -0500 Date: Tue, 13 Dec 2016 09:04:14 +0100 From: Peter Zijlstra To: Linus Torvalds Cc: Thomas Gleixner , LKML , Andrew Morton , Ingo Molnar , "H. Peter Anvin" Subject: Re: [GIT pull] x86/cache: Updates for 4.10 Message-ID: <20161213080414.GT3207@twins.programming.kicks-ass.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 911 Lines: 22 On Mon, Dec 12, 2016 at 08:26:50PM -0800, Linus Torvalds wrote: > On Mon, Dec 12, 2016 at 1:53 AM, Thomas Gleixner 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).