From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753333AbaHMQar (ORCPT ); Wed, 13 Aug 2014 12:30:47 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:60613 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753177AbaHMQap (ORCPT ); Wed, 13 Aug 2014 12:30:45 -0400 Date: Wed, 13 Aug 2014 18:30:15 +0200 From: Peter Zijlstra To: "Paul E. McKenney" Cc: Steven Rostedt , linux-kernel@vger.kernel.org, mingo@kernel.org, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com, jacob.jun.pan@linux.intel.com Subject: Re: [PATCH v5 tip/core/rcu 15/16] rcu: Make RCU-tasks wait for idle tasks Message-ID: <20140813163015.GT9918@twins.programming.kicks-ass.net> References: <20140811224840.GA25594@linux.vnet.ibm.com> <1407797345-28227-1-git-send-email-paulmck@linux.vnet.ibm.com> <1407797345-28227-15-git-send-email-paulmck@linux.vnet.ibm.com> <20140813081215.GB9918@twins.programming.kicks-ass.net> <20140813124818.GQ4752@linux.vnet.ibm.com> <20140813134025.GN9918@twins.programming.kicks-ass.net> <20140813095132.56d288f2@gandalf.local.home> <20140813140705.GO9918@twins.programming.kicks-ass.net> <20140813101301.08019895@gandalf.local.home> <20140813144332.GW4752@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="F0/awBnMJF6bn4Az" Content-Disposition: inline In-Reply-To: <20140813144332.GW4752@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --F0/awBnMJF6bn4Az Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Aug 13, 2014 at 07:43:32AM -0700, Paul E. McKenney wrote: > o drivers/acpi/acpi_pad.c, power_saving_thread(). >=20 > Looks like a kthread that does idle injection. Currently, RCU > sees it as not a quiescent state. Would it kill these guys to > put in a comment or two about what this is for??? >=20 > So adding rcu_idle_enter() and rcu_idle_exit() here might > actually fix a bug, though it is not clear how long this thing > actually runs. If only for a few milliseconds, no harm done. >=20 > o drivers/thermal/intel_powerclamp.c, clamp_thread(). >=20 > Looks similar to power_saving_thread(), but for thermal control. > Probably short term, shouldn't be a problem either way. >=20 There's patches somewhere that make that go-away https://lkml.org/lkml/2014/6/4/56 Jacob was going to look at that. --F0/awBnMJF6bn4Az Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJT65KXAAoJEHZH4aRLwOS6z0MQAIuCshiehBSTTBd+cKyI3hwV /mmHmnDBsgSYp56nZd9ul3FKMqsKvS/w5q5Ig6TXxVkeuNmc6mcP79xNrByDAdwL IsflGB+V47+IbyXCVQQA1cLmEiZCZluJvmoZzgJHdtPUJxtXe2zsAtESbr46YAFT qN2N9h0A0T8PeFcAQuY64xAEyKJ/9JRPsMYoYZpjJbn84AFEoYNqT7Qjh4CBlD1h LIuFzV08f3hVEfSvG6VhWXDF2OKeoXH3nO6l3PJQNOSQct/v2pHQw+r2CAaDDK/7 xqgApUowqP1OMtw4QQ+YMMKFNcahNwBuVmE+dZXW+2ICP+H4C0By2QRJIFCM7TYi NBcOttXkNOzYHC+Yku61ppjbvjZnRkJmWkHh7H1M7KqE/BvL6/71uwZUkRozlMwf JZuBrP71oHgz7MotbgwROOEBozpY8+Xs6u2s4w+yybp57Rjvy4doqmGU91Fr9han P23y/NAphABWdhf494FqiCWw0dbMLnuKu1IyajpAJgzDl3MLq7/S4gN/1gII8bx/ ETm2M9E3Cuyy+D31qTEQinEXTGpH2GINCr0ifqNImJZnNQ21ouQ7vkQMf2YumcuP 4dfKiR/ep6dzcutX4KUuw8sqxuCNg2B6NM756qeJWbOeEo3v91rUkeCz7MfzjTe+ 7PWdZOQotq4TibS6uF/k =bqDG -----END PGP SIGNATURE----- --F0/awBnMJF6bn4Az--