From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753175AbaHMQfq (ORCPT ); Wed, 13 Aug 2014 12:35:46 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:34696 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751145AbaHMQfp (ORCPT ); Wed, 13 Aug 2014 12:35:45 -0400 Date: Wed, 13 Aug 2014 18:35:22 +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 Subject: Re: [PATCH v5 tip/core/rcu 15/16] rcu: Make RCU-tasks wait for idle tasks Message-ID: <20140813163522.GU9918@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="6rtPZF7Topj4j03h" 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 --6rtPZF7Topj4j03h 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: > So the first three look OK to hook rcu_idle_enter() and rcu_idle_exit() > into, but the last two don't look so good. >=20 > That said, if you are OK not tracing the stuff under stop_critical_timing= s(), > then I can use the RCU dyntick-idle state and not wake anything up. Either way, Steve could easily whip up a debug thing that could validate that. Simply WARN whenever an __mcount happens when under rcu_idle. And if we make these idle functions small enough that should not be a problem at all. --6rtPZF7Topj4j03h Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJT65PKAAoJEHZH4aRLwOS6vY8P/R2G0Ic4OParCepaBB7WUVX6 LyM04bSFt233WYmch+WzOosTAM7lWKKGx4mmy+YYY0tj4ITTTyculu73+oys+sa/ y8SWYa7A5UdwBZ0JX3DEZFiGmfdMlvweGKI2dXmq4QP+6RRz+ln75pW0XsWBMO6y ic6ju7tINNObN1sXpoMlNcNj5NRZfNqlas0eAOFT+k7GoixtZU+r+xrxuozQM/GY e9lGHvP9+Rj3IMolotBf4bVramZ8WaXJ0jr2OBae7gHQj+pG6RTND6z7xNpp34e8 Xr9Z+Ga+ge2KXGKHaJPf8/Y2SwkOt0hp2lHtpVIoHa/rVMIqsYnAsMxewbvEDoIO 7myODkJq/WR0BlB+XPZen5oSXHmO4N70a28K0zHNpkZ8ZOZfP+QXTQnSgbB9afZa HFGHjqEzR1Pc40st862Qz7RPNR5gV1ZH5NmQ6uM1MgsbPzYEWJ6QxogFcxMgwAC/ AiWDak2glMMpazm7akIeaDf8roZpvlEZqDVJRzmOQaeGYg5fXHrgo8fZfWYttuMw a+aJLAIiiblZx0/MoULSWYmZmE7CHNgbxR4gAWR6qsv/ZWX/UsagWB49vNkQGNR/ mmLb0QXTjaS8ZUfp2T7huR8rTTjz8pO8JggOvtAyZyZJMhNeMLqrynWYe9AMlhxT jvFl9hP19Mz2L+QQEhLh =6hHh -----END PGP SIGNATURE----- --6rtPZF7Topj4j03h--