Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751958AbdC0SGO (ORCPT ); Mon, 27 Mar 2017 14:06:14 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:42988 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751785AbdC0SGE (ORCPT ); Mon, 27 Mar 2017 14:06:04 -0400 Date: Mon, 27 Mar 2017 19:05:30 +0100 From: Mark Brown To: Peter Zijlstra Cc: Juri Lelli , mingo@redhat.com, rjw@rjwysocki.net, 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" Message-ID: <20170327180530.2hhthml46o3ey56a@sirena.org.uk> References: <20170324140900.7334-1-juri.lelli@arm.com> <20170324140900.7334-4-juri.lelli@arm.com> <20170327165011.dpip23cyolnleas6@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="vfh5i47o46hgxcor" Content-Disposition: inline In-Reply-To: <20170327165011.dpip23cyolnleas6@hirez.programming.kicks-ass.net> X-Cookie: No shirt, no shoes, no service. User-Agent: NeoMutt/20161126 (1.7.1) X-SA-Exim-Connect-IP: 2001:470:1f1d:6b5::3 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Re: [RFD PATCH 3/5] sched/cpufreq_schedutil: make worker kthread be SCHED_DEADLINE X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: No (on mezzanine.sirena.org.uk); Unknown failure Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1465 Lines: 39 --vfh5i47o46hgxcor Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Mar 27, 2017 at 06:50:11PM +0200, Peter Zijlstra wrote: > Taken together this seems to suggest we can rework cpufreq drivers to > function in-context, either directly push the packet on the bus if > available, or queue it and let whoever owns it sort it without blocking. Note that this isn't really cpufreq's problem per se, cpufreq is going to work out what voltage it wants then tell the regulator API to do that which will in turn go communicate with the PMIC somehow, typically with regmap over I2C or SPI. All those layers use mutexes by default. > So if we can make all that work, we can do away with this horrible > horrible kthread. Which is, IMO, a much better solution. > Thoughts? I think it's doable, but a lot of work especially in the regulator code. --vfh5i47o46hgxcor Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAljZVGkACgkQJNaLcl1U h9AVmwf/bwPFFXYQSLi0kTijf6+HO0CBPv162MkTMT4vpY1UXZ47IvCo/LZsD74i bfJo62Wu3R+wq/79nEqkCKocexMP3RKop5CpjBuDindRrHFhpMXifaB64IX3MBIp v6SoAiMC012pTbbO+jWet+P5hz/5JihNhUxlY0tRMlyriYtPRU3ynknrRJ8Gxme8 jECGK9g9l/coVAtUv3ahpU5fG9SKrK7xlyZmG0d4bPbQMoDl6ocuSCc+D48KyhvR PUcLeIDmgdAtmZbOb3KFsJnBzr89u+/1KMvmRI0rxLPjGuE85zJ8q8coMM/qSlG2 TBJL3Jl47lbjcpjjxANcd6fhF8nuPQ== =3oHq -----END PGP SIGNATURE----- --vfh5i47o46hgxcor--