From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: [PATCH] sched/rt: RT_RUNTIME_GREED sched feature Date: Mon, 7 Nov 2016 13:30:46 -0500 Message-ID: <20161107133046.7e4458c1@gandalf.local.home> References: <20161107122221.299d026a@tagon> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Daniel Bristot de Oliveira , Ingo Molnar , Peter Zijlstra , Christoph Lameter , linux-rt-users , LKML To: Clark Williams Return-path: Received: from smtprelay0126.hostedemail.com ([216.40.44.126]:40729 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932846AbcKGSau (ORCPT ); Mon, 7 Nov 2016 13:30:50 -0500 In-Reply-To: <20161107122221.299d026a@tagon> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Mon, 7 Nov 2016 12:22:21 -0600 Clark Williams wrote: > I'm still reviewing the patch, but I have to wonder why bother with making it a scheduler feature? > > The SCHED_FIFO definition allows a fifo thread to starve others > because a fifo task will run until it yields. Throttling was added as > a safety valve to allow starved SCHED_OTHER tasks to get some cpu > time. Adding this unconditionally gets us a safety valve for > throttling a badly written fifo task, but allows the fifo task to > continue to consume cpu cycles if it's not starving anyone. > > Or am I missing something that's blazingly obvious? Or I say make it the default. If people want the old behavior, they can modify SCHED_FEATURES to do so. -- Steve