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=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED 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 6100BC10F13 for ; Tue, 16 Apr 2019 12:43:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 392EE20868 for ; Tue, 16 Apr 2019 12:43:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729125AbfDPMnW (ORCPT ); Tue, 16 Apr 2019 08:43:22 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:48831 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726907AbfDPMnW (ORCPT ); Tue, 16 Apr 2019 08:43:22 -0400 Received: from localhost ([127.0.0.1] helo=vostro.local) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1hGNQk-0008TR-Ad; Tue, 16 Apr 2019 14:43:18 +0200 From: John Ogness To: Sebastian Andrzej Siewior Cc: Peter Zijlstra , hpa@zytor.com, mingo@kernel.org, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Subject: Re: [tip:sched/core] sched/core: Document that RT task priorities are 1...99 References: <20190403210821.10916-1-bigeasy@linutronix.de> <20190416093634.GS11158@hirez.programming.kicks-ass.net> <20190416094727.xanzq5t2xjuflcbt@linutronix.de> Date: Tue, 16 Apr 2019 14:43:15 +0200 In-Reply-To: <20190416094727.xanzq5t2xjuflcbt@linutronix.de> (Sebastian Andrzej Siewior's message of "Tue, 16 Apr 2019 11:47:27 +0200") Message-ID: <87tveyt924.fsf@linutronix.de> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019-04-16, Sebastian Andrzej Siewior wrote: > On 2019-04-16 11:36:34 [+0200], Peter Zijlstra wrote: >> On Tue, Apr 16, 2019 at 01:13:11AM -0700, tip-bot for Sebastian Andrzej Siewior wrote: >> > Commit-ID: 37a8f8590f307db8f8cfa62dfd82b3fc0978607c >> > Gitweb: https://git.kernel.org/tip/37a8f8590f307db8f8cfa62dfd82b3fc0978607c >> > Author: Sebastian Andrzej Siewior >> > AuthorDate: Wed, 3 Apr 2019 23:08:21 +0200 >> > Committer: Ingo Molnar >> > CommitDate: Tue, 16 Apr 2019 10:06:08 +0200 >> > >> > sched/core: Document that RT task priorities are 1...99 >> > >> > John identified three files which claim that RT task priorities start at >> > zero. As far as I understand, 0 is used for DL and has nothing to do >> > wihich RT priorities as identified by the RT policy. >> >> DL is -1, 0 is still very much FIFO/FF > > but it can't be set. The lowest we can set is 1. Is this a bug then? I think it is important to clarify if you are talking about userspace or kernel. They are different. For userspace 1(low)-99(high) is allowed. For kernel 0(high)-98(low) is used. John Ogness