Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934250AbdC3PuP (ORCPT ); Thu, 30 Mar 2017 11:50:15 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:41036 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933356AbdC3PuN (ORCPT ); Thu, 30 Mar 2017 11:50:13 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 30 Mar 2017 08:50:11 -0700 From: Vikram Mulukutla To: "Rafael J. Wysocki" Cc: Juri Lelli , Peter Zijlstra , mingo@redhat.com, viresh.kumar@linaro.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, tglx@linutronix.de, vincent.guittot@linaro.org, rostedt@goodmis.org, luca.abeni@santannapisa.it, claudio@evidence.eu.com, tommaso.cucinotta@santannapisa.it, bristot@redhat.com, mathieu.poirier@linaro.org, tkjos@android.com, joelaf@google.com, andresoportus@google.com, morten.rasmussen@arm.com, dietmar.eggemann@arm.com, patrick.bellasi@arm.com, Ingo Molnar , "Rafael J . Wysocki" , Mark Brown , linux-kernel-owner@vger.kernel.org Subject: Re: [RFD PATCH 3/5] sched/cpufreq_schedutil: make worker kthread be SCHED_DEADLINE In-Reply-To: <1721120.3Th1GMboUn@aspire.rjw.lan> References: <20170324140900.7334-1-juri.lelli@arm.com> <37277532.TseFq3j8HT@aspire.rjw.lan> <20170327171336.GD10289@e106622-lin> <1721120.3Th1GMboUn@aspire.rjw.lan> Message-ID: User-Agent: Roundcube Webmail/1.2.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 939 Lines: 34 > OK > > So there are two pieces here. > > One is that if we want *all* drivers to work with schedutil, we need to > keep > the kthread for the ones that will never be reworked (because nobody > cares > etc). But then perhaps the kthread implementation may be left alone > (because > nobody cares etc). > > The second one is that there are drivers operating in-context that work > with > schedutil already, so I don't see major obstacles to making more > drivers work > that way. That would be only a matter of reworking the drivers in > question. > > Thanks, > Rafael There are some MSM platforms that do need a kthread and would love to use schedutil. This is all mainly due to the point that Vincent raised; having to actually wait for voltage transitions before clock switches. I can't speak about the future, but that's the situation right now. Leaving the kthread alone for now would be appreciated! Thanks, Vikram