From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH v4 2/5] build: Hook the schedulers into Kconfig Date: Sat, 9 Jan 2016 18:08:59 +0000 Message-ID: <56914CBB.2050406@citrix.com> References: <1452288166-43501-1-git-send-email-jonathan.creekmore@gmail.com> <1452288166-43501-3-git-send-email-jonathan.creekmore@gmail.com> <56911EAA.8030707@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aHxwm-0007wg-Ut for xen-devel@lists.xenproject.org; Sat, 09 Jan 2016 18:09:05 +0000 In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jonathan Creekmore Cc: George Dunlap , xen-devel@lists.xenproject.org, Dario Faggioli List-Id: xen-devel@lists.xenproject.org On 09/01/16 17:50, Jonathan Creekmore wrote: > Andrew Cooper writes: > >> On 08/01/16 21:22, Jonathan Creekmore wrote: >>> +# Enable schedulers >>> +menu "Schedulers" >>> + visible if EXPERT = "y" >>> + >>> +config SCHED_CREDIT >>> + bool "Credit scheduler support" >>> + default y >>> + ---help--- >>> + The traditional credit scheduler is a general purpose scheduler. >>> + >>> + If unsure, say Y. >>> + >>> +config SCHED_CREDIT2 >>> + bool "Credit2 scheduler support (EXPERIMENTAL)" >>> + default y >>> + ---help--- >>> + The credit2 scheduler is a general purpose scheduler that is >>> + optimized for lower latency and higher VM density. >>> + >>> + If unsure, say Y. >>> + >>> +config SCHED_RTDS >>> + bool "RTDS scheduler support (EXPERIMENTAL)" >>> + default y >>> + ---help--- >>> + The RTDS scheduler is a soft and firm real-time scheduler for >>> + multicore, targeted for embedded, automotive, graphics and gaming >>> + in the cloud, and general low-latency workloads. >>> + >>> + If unsure, say N. >>> + >>> +config SCHED_ARINC653 >>> + bool "ARINC653 scheduler support (EXPERIMENTAL)" >>> + default y >>> + ---help--- >>> + The ARINC653 scheduler is a hard real-time scheduler for single >>> + cores, targeted for avionics, drones, and medical devices. >>> + >>> + If unsure, say N. >> Sorry for not noticing this before. The "If unsure, say $X" should >> really match the default value. >> >> On the other hand, given that we are hiding all these options behind >> CONFIG_EXPERT, I am not sure that we need "If unsure" clauses. Anyone >> who isn't sure shouldn't have turned on CONFIG_EXPERT to start with. > I was trying to mimic language that the Linux kernel would use for > EXPERIMENTAL marked items. Given the documentation on the wiki, I think > marking those three schedulers EXPERIMENTAL is correct. I concur about their status. > Given that, I > still think that the language saying "If unsure, say N" is correct (the > thought being, the only people who should be messing with the > EXPERIMENTAL schedulers are people developing or specifically testing > them). The *only* reason I marked them default of Y is to keep backwards > compatibility with the current build. Also very important. > > However, if you would prefer me to remove the "If unsure" language > completely, I can do that. The text came in before the whole > CONFIG_EXPERT flag did. I would suggest dropping it (although you probably want to wait for opinions from others). We have already diverged from Linux with regards to the EXPERT flag; people who are unsure cannot accidentally get here. ~Andrew