Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935128AbdCVORB (ORCPT ); Wed, 22 Mar 2017 10:17:01 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:37176 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934894AbdCVOQj (ORCPT ); Wed, 22 Mar 2017 10:16:39 -0400 Date: Wed, 22 Mar 2017 15:16:26 +0100 From: Peter Zijlstra To: Joel Fernandes Cc: linux-kernel@vger.kernel.org, Paul Turner , Dietmar Eggemann , Juri Lelli , Patrick Bellasi , Ingo Molnar Subject: Re: [PATCH] sched: fair: Improve PELT decay_load calculation comments Message-ID: <20170322141626.isj3dlrimppwq2xv@hirez.programming.kicks-ass.net> References: <20170310202341.11449-1-joelaf@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170310202341.11449-1-joelaf@google.com> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 447 Lines: 12 On Fri, Mar 10, 2017 at 12:23:41PM -0800, Joel Fernandes wrote: > The PELT decay_load comments are a bit confusing, first of all > the 1/2^N should be (1/2)^N so that the reader doesn't get confused. I'm thinking you're confused. They're identical. (1/2)^N = (2^-1)^N = 2^-N = 1/2^N > Secondly, the y^N splitting into a 2-part decay factor deserves > a better explanation. This patch improves the comments. I find its actually harder to read.