From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762386AbdAEJ1o (ORCPT ); Thu, 5 Jan 2017 04:27:44 -0500 Received: from mail-qk0-f181.google.com ([209.85.220.181]:35015 "EHLO mail-qk0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1033479AbdAEJ0x (ORCPT ); Thu, 5 Jan 2017 04:26:53 -0500 Subject: Re: [RFC PATCH 0/7] locking/rtqspinlock: Realtime queued spinlocks To: Waiman Long , Peter Zijlstra References: <1483466430-8028-1-git-send-email-longman@redhat.com> <20170104124929.GI25813@worktop.programming.kicks-ass.net> <57c0a6e1-1fab-b8d4-2a68-02cc1ebf7ce6@redhat.com> Cc: Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , linux-kernel@vger.kernel.org, Steven Rostedt From: Daniel Bristot de Oliveira Message-ID: <43a38563-266c-90f5-88d2-6c4164d97392@redhat.com> Date: Thu, 5 Jan 2017 10:26:37 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <57c0a6e1-1fab-b8d4-2a68-02cc1ebf7ce6@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/04/2017 04:25 PM, Waiman Long wrote: >> OK, so a single numerical field isn't sufficient to describe priority >> anymore, since we added DEADLINE support things have gotten a lot more >> complex. > From what I read from the code, DL tasks all have the same priority that > is higher than any of the RT tasks. So you mean DL tasks have other > property that kind of categorizing them into different sub-priorities > that is not being reflected in their priority level. Is that right? DL tasks are scheduled according to their absolute deadline, which stored in the u64 curr->dl.deadline. It is more complex because the priority of a deadline task is always changing. The priority of a DL task changes on every new periodic/sporadic replenishment/activation. -- Daniel