From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3467FC4740A for ; Mon, 7 Oct 2019 09:13:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F0EC2133F for ; Mon, 7 Oct 2019 09:13:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727442AbfJGJNZ (ORCPT ); Mon, 7 Oct 2019 05:13:25 -0400 Received: from foss.arm.com ([217.140.110.172]:58160 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727307AbfJGJNZ (ORCPT ); Mon, 7 Oct 2019 05:13:25 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9531C1570; Mon, 7 Oct 2019 02:13:24 -0700 (PDT) Received: from [10.1.194.37] (e113632-lin.cambridge.arm.com [10.1.194.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3F5653F68E; Mon, 7 Oct 2019 02:13:24 -0700 (PDT) Subject: Re: Question about sched_prio_to_weight values To: Francesco Poli , linux-kernel@vger.kernel.org References: <20191007003205.8888ac99da2dd732b6198387@paranoici.org> From: Valentin Schneider Message-ID: <506d5ee6-246a-a03d-ea11-227ff4de1467@arm.com> Date: Mon, 7 Oct 2019 10:13:23 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20191007003205.8888ac99da2dd732b6198387@paranoici.org> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Francesco, On 06/10/2019 23:32, Francesco Poli wrote: [...] > I searched the web and the mailing list archives, but I failed to find > an answer to this question. Could someone please explain me how those > numbers were picked? > Following the blame rabbit hole I found this: 254753dc321e ("sched: make the multiplication table more accurate") https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=254753dc321ea2b753ca9bc58ac329557a20efac which sounds like it would explain some small deltas if compared to a formula that is set in stone. Hope that helps. > Thanks for your time! > >