Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752930AbbKXHgx (ORCPT ); Tue, 24 Nov 2015 02:36:53 -0500 Received: from mga02.intel.com ([134.134.136.20]:33356 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752665AbbKXHgm (ORCPT ); Tue, 24 Nov 2015 02:36:42 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,338,1444719600"; d="scan'208";a="858499809" Date: Tue, 24 Nov 2015 15:31:24 +0800 From: Chao Peng To: Thomas Gleixner Cc: LKML , Peter Zijlstra , x86@kernel.org, Marcelo Tosatti , Luiz Capitulino , Vikas Shivappa , Tejun Heo , Yu Fenghua Subject: Re: [RFD] CAT user space interface revisited Message-ID: <20151124073124.GA17000@pengc-linux.bj.intel.com> Reply-To: Chao Peng References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1530 Lines: 37 On Wed, Nov 18, 2015 at 07:25:03PM +0100, Thomas Gleixner wrote: > > Let's look at partitioning itself. We have two options: > > 1) Per task partitioning > > 2) Per CPU partitioning > > So far we only talked about #1, but I think that #2 has a value as > well. Let me give you a simple example. I would second this. In practice per CPU partitioning is useful for realtime as well. And I can see three possible solutions: 1) What you suggested below, to address both problems in one framework. But I wonder if it would end with too complex. 2) Achieve per CPU partitioning with per task partitioning. For example, if current CAT patch can solve the kernel threads problem, together with CPU pinning, we then can set a same CBM for all the tasks/kernel threads run on an isolated CPU. 3) I wonder if it feasible to separate the two requirements? For example, divides the work into three components: rdt-base, per task interface (current cgroup interface/IOCTL or something) and per CPU interface. The two interfaces are exclusive and selected at build time. One thing to reject this option would be even with per CPU partitioning, we still need per task partitioning, in that case we will go to option 1) again. Thanks, Chao -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/