From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938394AbdAEKRz (ORCPT ); Thu, 5 Jan 2017 05:17:55 -0500 Received: from mail-qk0-f174.google.com ([209.85.220.174]:35003 "EHLO mail-qk0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S938356AbdAEKQx (ORCPT ); Thu, 5 Jan 2017 05:16:53 -0500 Subject: Re: [RFC PATCH 6/7] locking/rtqspinlock: Voluntarily yield CPU when need_sched() To: Waiman Long , Peter Zijlstra , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" References: <1483466430-8028-1-git-send-email-longman@redhat.com> <1483466430-8028-7-git-send-email-longman@redhat.com> Cc: linux-kernel@vger.kernel.org From: Daniel Bristot de Oliveira Message-ID: <423f5394-e1a1-06b5-8bb0-c9f77945dbdb@redhat.com> Date: Thu, 5 Jan 2017 11:16:42 +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: <1483466430-8028-7-git-send-email-longman@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/03/2017 07:00 PM, Waiman Long wrote: > For nested spinlock with outer lock acquired, it will > + * boost its priority to the highest RT priority level to try to acquire the > + * inner lock, finish up its work, release the locks and reenable preemption. DL scheduler turns the definition of "highest RT priority" more complicated. One may try to move a task to the DL class with a very closer deadline, but a DL task can always be rejected by the admission test.... -- Daniel