From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932464AbaJVUHk (ORCPT ); Wed, 22 Oct 2014 16:07:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52713 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932323AbaJVUHj (ORCPT ); Wed, 22 Oct 2014 16:07:39 -0400 Message-ID: <54480E58.5060600@redhat.com> Date: Wed, 22 Oct 2014 16:06:48 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1 MIME-Version: 1.0 To: Mike Turquette , peterz@infradead.org, mingo@kernel.org CC: linux-kernel@vger.kernel.org, preeti@linux.vnet.ibm.com, Morten.Rasmussen@arm.com, kamalesh@linux.vnet.ibm.com, efault@gmx.de, nicolas.pitre@linaro.org, linaro-kernel@lists.linaro.org, daniel.lezcano@linaro.org, dietmar.eggemann@arm.com, pjt@google.com, bsegall@google.com, vincent.guittot@linaro.org, patches@linaro.org, tuukka.tikkanen@linaro.org, amit.kucheria@linaro.org Subject: Re: [PATCH RFC 5/7] sched: cfs: cpu frequency scaling arch functions References: <1413958051-7103-1-git-send-email-mturquette@linaro.org> <1413958051-7103-6-git-send-email-mturquette@linaro.org> In-Reply-To: <1413958051-7103-6-git-send-email-mturquette@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 10/22/2014 02:07 AM, Mike Turquette wrote: > arch_eval_cpu_freq and arch_scale_cpu_freq are added to allow the > scheduler to evaluate if cpu frequency should change and to invoke > that change from a safe context. > > They are weakly defined arch functions that do nothing by default. > A CPUfreq governor could use these functions to implement a > frequency scaling policy based on updates to per-task statistics or > updates to per-cpu utilization. > > As discussed at Linux Plumbers Conference 2014, the goal will be > to focus on a single cpu frequency scaling policy that works for > everyone. That may mean that the weak arch functions definitions > can be removed entirely and a single policy implements that logic > for all architectures. On virtual machines, we probably want to use both frequency and steal time to calculate the factor. - -- All rights reversed -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJUSA5XAAoJEM553pKExN6DeRYH/jeXImjO2/WZFp82Yv6ukMxI r8/kzrLMA+NS1XXCWYIcOiBqReEabkZZmypt21Tdnpkvi4GbZPpG0PEApSvOfqWE w71J87cpMGV/e4uLcBDcvgHJX8RBQLO/ZqDcMm+zcSoeJ3G3NMK2YlZp3Uf8xqcB tE2VGW7o2yEqNJL1fqYb++3upQmc10vIFqxVIJfP+TqZRyaVP+5kBqOMDTWb5qCV qZjBKe1jDX5sLLGfY0ddAeuUH1iEJBIUMCcr027ezcqRp4YoqIrHRInHmNxEs5Az 9PN8N0yGgqhvkcCfXG7He+tQBHECOnjyQlrM/2K8Cw11RziwDkC/yYIp3DPgjxc= =f/8V -----END PGP SIGNATURE-----