From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753264AbaKCPvr (ORCPT ); Mon, 3 Nov 2014 10:51:47 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:40509 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752272AbaKCPvl (ORCPT ); Mon, 3 Nov 2014 10:51:41 -0500 Date: Mon, 3 Nov 2014 16:51:29 +0100 From: Peter Zijlstra To: Vincent Guittot Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, preeti@linux.vnet.ibm.com, Morten.Rasmussen@arm.com, kamalesh@linux.vnet.ibm.com, linux@arm.linux.org.uk, linux-arm-kernel@lists.infradead.org, riel@redhat.com, efault@gmx.de, nicolas.pitre@linaro.org, linaro-kernel@lists.linaro.org Subject: Re: [PATCH v8 10/10] sched: make scale_rt invariant with frequency Message-ID: <20141103155129.GK12706@worktop.programming.kicks-ass.net> References: <1414745252-4895-1-git-send-email-vincent.guittot@linaro.org> <1414745252-4895-11-git-send-email-vincent.guittot@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1414745252-4895-11-git-send-email-vincent.guittot@linaro.org> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 31, 2014 at 09:47:32AM +0100, Vincent Guittot wrote: > The call to arch_scale_frequency_capacity in the rt scheduling path might be > a concern for RT folks because I'm not sure whether we can rely on > arch_scale_freq_capacity to be short and efficient ? Well, you put it in quite a hot path on the CFS side too, so it had better be blazing fast anyhow. That said, can you move all the running + invariance bits at the beginning of the patch set, these appear to be the least controversial bits and 'desired' by quite a few people, so we'll try and get those agreed upon and merged first.