From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754031AbbJPJu0 (ORCPT ); Fri, 16 Oct 2015 05:50:26 -0400 Received: from casper.infradead.org ([85.118.1.10]:54021 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752495AbbJPJuY (ORCPT ); Fri, 16 Oct 2015 05:50:24 -0400 Date: Fri, 16 Oct 2015 11:50:22 +0200 From: Peter Zijlstra To: Marcelo Tosatti Cc: Thomas Gleixner , Fenghua Yu , H Peter Anvin , Ingo Molnar , linux-kernel , x86 , Vikas Shivappa Subject: Re: [PATCH V15 00/11] x86: Intel Cache Allocation Technology Support Message-ID: <20151016095022.GP3816@twins.programming.kicks-ass.net> References: <1443766185-61618-1-git-send-email-fenghua.yu@intel.com> <20151013213125.GA16200@amt.cnet> <20151015113614.GL3816@twins.programming.kicks-ass.net> <20151016022851.GA9008@amt.cnet> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151016022851.GA9008@amt.cnet> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 15, 2015 at 11:28:52PM -0300, Marcelo Tosatti wrote: > On Thu, Oct 15, 2015 at 01:36:14PM +0200, Peter Zijlstra wrote: > > On Tue, Oct 13, 2015 at 06:31:27PM -0300, Marcelo Tosatti wrote: > > > I am rewriting the interface with ioctls, with commands similar to the > > > syscall interface proposed. > > > > Which is horrible for other use cases. I really don't see the problem > > with the cgroup stuff. > > Can you detail what "horrible" means? Say an RT scenario; you set up your machine with cgroups. You create a cpuset with is disjoint from the others, you frob around with the cpu cgroup, etc.. So once you're all done, you start your RT app into a cgroup. But oh, fail, now you have to go muck about with ioctl()s to get the cache allocation cruft to work.