Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751680AbbHBQcC (ORCPT ); Sun, 2 Aug 2015 12:32:02 -0400 Received: from mail-yk0-f169.google.com ([209.85.160.169]:34195 "EHLO mail-yk0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751316AbbHBQcA (ORCPT ); Sun, 2 Aug 2015 12:32:00 -0400 Date: Sun, 2 Aug 2015 12:31:57 -0400 From: Tejun Heo To: Vikas Shivappa Cc: Vikas Shivappa , linux-kernel@vger.kernel.org, x86@kernel.org, hpa@zytor.com, tglx@linutronix.de, mingo@kernel.org, peterz@infradead.org, matt.fleming@intel.com, will.auld@intel.com, glenn.p.williamson@intel.com, kanaka.d.juvva@intel.com Subject: Re: [PATCH 5/9] x86/intel_rdt: Add new cgroup and Class of service management Message-ID: <20150802163157.GB32599@mtj.duckdns.org> References: <1435789270-27010-1-git-send-email-vikas.shivappa@linux.intel.com> <1435789270-27010-6-git-send-email-vikas.shivappa@linux.intel.com> <20150730194458.GD3504@mtj.duckdns.org> 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: 1226 Lines: 27 Hello, Vikas. On Fri, Jul 31, 2015 at 09:24:58AM -0700, Vikas Shivappa wrote: > Yes today we dont have an alternative interface - but we can always build > one. We simply dont have it because till now Linux kernel just tolerated the > degradation that could have occured by cache contention and this is the > first interface we are building. But we're doing it the wrong way around. You can do most of what cgroup interface can do with systemcall-like interface with some inconvenience. The other way doesn't really work. As I wrote in the other reply, cgroups is a horrible programmable interface and we don't want individual applications to interact with it directly and CAT's use cases most definitely include each application programming its own cache mask. Let's build something which is simple and can be used easily first. If this turns out to be widely useful and an overall management capability over it is wanted, we can consider cgroups then. Thanks. -- tejun -- 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/