From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752809AbaHMOHU (ORCPT ); Wed, 13 Aug 2014 10:07:20 -0400 Received: from casper.infradead.org ([85.118.1.10]:44679 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751652AbaHMOHS (ORCPT ); Wed, 13 Aug 2014 10:07:18 -0400 Date: Wed, 13 Aug 2014 16:07:05 +0200 From: Peter Zijlstra To: Steven Rostedt Cc: "Paul E. McKenney" , 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 Subject: Re: [PATCH v5 tip/core/rcu 15/16] rcu: Make RCU-tasks wait for idle tasks Message-ID: <20140813140705.GO9918@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> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="zvbl/8tVKAFcMeVq" Content-Disposition: inline In-Reply-To: <20140813095132.56d288f2@gandalf.local.home> 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 --zvbl/8tVKAFcMeVq Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Aug 13, 2014 at 09:51:32AM -0400, Steven Rostedt wrote: > I still need to look at the patches, but if this is just for the idle > case, then we don't need it. The idle case can be solved with a simple > sched_on_each_cpu(). I need a way to solve waiting for processes to > finish from a preemption point. >=20 > That's all I want, and if we can remove the "idle" case and document it > well that it's not covered and a sched_on_each_cpu() may be needed, > then I'm fine with that. >=20 > sched_on_each_cpu(dummy_op); > call_rcu_tasks(free_tramp); Sure, but why not dtrt and push rcu_idle hooks all the way down into the idle drivers if and where appropriate? There isn't _that_ much idle driver code. Also, some stuff should be cleaned up; we're already calling stop_critical_timings() in the generic idle code, and then calling it again in the cpuidle drivers. --zvbl/8tVKAFcMeVq Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJT63EJAAoJEHZH4aRLwOS6sTcQAK4N7zGLEdN1WowgESfGdnko LWBVt9pqWNfRcb2VFtP3lj0eWClUsuVNLQWwLIc2LcWepmy3CE8Bg8hmGTSXNFMR z3ii0C6TiwX3PzakKseMuE62lK3n5oHLMIZmg92NrPL4BSrutFR1/11kIhN83fpE GFL3/frC0M28V2Qfe0BQovqmQsA/942A4ABKyGo8FOCk4LoJj+gPzgUtQsgc696t XLg1zvTsxP7O5qGt7CGJjrdkykwr2troWjVGZOkLYcczLNLVqxChZK7rmT+Sezp1 DfDqfAb0U07HutVYHwE9loTPfnqeAbxEPz5/Cwd5+Y2qsWSHLYFkxHqflVeCgKwP Zdz0BinHqBl7Wy4qXaTHP7uxERPOLZSUpymdDk/sOQ9wPG+y2O73GmW7EobdrZ1Y NabQaZHym/BPZyF1jgZP+YRbgNYzVD2a0sv5GFGeI/2LkwRIsgWfn3P97AOfE0ay 4p7ykOERWmae02gtV9Vjy0i3RUjEbrtq+jvzs/EoJ6GzNkAIVUkphf17ZU2jVA/6 WxPU9gZm8LPy3o1LoP1LTuP3Wgu5YV1+geqsqvyFVqGEc2xdpyE/D9So2HM82uGL s2R+cEmBZzNQRJolcYx9zHLScir+fqmqfc0xKvK6mAWCNvyhZ9//8gMV2ZF0alAn rIKunSJ9/RGtNK71PLeo =gzwU -----END PGP SIGNATURE----- --zvbl/8tVKAFcMeVq--