From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934399AbbCDKyp (ORCPT ); Wed, 4 Mar 2015 05:54:45 -0500 Received: from cpsmtpb-ews04.kpnxchange.com ([213.75.39.7]:58394 "EHLO cpsmtpb-ews04.kpnxchange.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934374AbbCDKyl (ORCPT ); Wed, 4 Mar 2015 05:54:41 -0500 Message-ID: <1425466477.2798.5.camel@tiscali.nl> Subject: Re: [PATCH tip/core/rcu 10/20] rcu: Provide diagnostic option to slow down grace-period initialization From: Paul Bolle To: "Paul E. McKenney" Cc: 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, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com Date: Wed, 04 Mar 2015 11:54:37 +0100 In-Reply-To: <1425404595-17816-10-git-send-email-paulmck@linux.vnet.ibm.com> References: <20150303174144.GA13139@linux.vnet.ibm.com> <1425404595-17816-1-git-send-email-paulmck@linux.vnet.ibm.com> <1425404595-17816-10-git-send-email-paulmck@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.11 (3.12.11-1.fc21) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 04 Mar 2015 10:54:40.0097 (UTC) FILETIME=[9D192510:01D05669] X-RcptDomain: vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org All I spotted is a silly typo. Paul E. McKenney schreef op di 03-03-2015 om 09:43 [-0800]: > --- a/lib/Kconfig.debug > +++ b/lib/Kconfig.debug > @@ -1257,6 +1257,30 @@ config RCU_TORTURE_TEST_RUNNABLE > Say N here if you want the RCU torture tests to start only > after being manually enabled via /proc. > > +config RCU_TORTURE_TEST_SLOW_INIT > + bool "Slow down RCU grace-period initialization to expose races" > + depends on RCU_TORTURE_TEST > + help > + This option makes grace-period initialization block for a > + few jiffies between initializing each pair of consecutive > + rcu_node structures. This helps to expose races involving > + grace-period initialization, in other words, it makes your > + kernel less stable. It can also greatly increase grace-period > + latency, especially on systems with large numbers of CPUs. > + This is useful when torture-testing RCU, but in almost no > + other circumstance. > + > + Say Y here if you want your system to crash and hang more often. (Did you ever consider going into marketing?) > + Say N if you want a sane system. > + > +config RCU_TORTURE_TEST_SLOW_INIT_DELAY > + int "How must to slow down RCU grace-period initialization" s/must/much/ > + range 0 5 > + default 0 > + help > + This option specifies the number of jiffies to wait between > + each rcu_node structure initialization. > + > config RCU_CPU_STALL_TIMEOUT > int "RCU CPU stall timeout in seconds" > depends on RCU_STALL_COMMON Paul Bolle