From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964938AbbEMN0o (ORCPT ); Wed, 13 May 2015 09:26:44 -0400 Received: from e39.co.us.ibm.com ([32.97.110.160]:47058 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753256AbbEMN0n (ORCPT ); Wed, 13 May 2015 09:26:43 -0400 Date: Wed, 13 May 2015 06:07:28 -0700 From: "Paul E. McKenney" To: josh@joshtriplett.org 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, 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 Subject: Re: [PATCH tip/core/rcu 2/3] rcutorture: Test both RCU-sched and RCU-bh for Tiny RCU Message-ID: <20150513130728.GX6776@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20150512224855.GA4776@linux.vnet.ibm.com> <1431470953-4910-1-git-send-email-paulmck@linux.vnet.ibm.com> <1431470953-4910-2-git-send-email-paulmck@linux.vnet.ibm.com> <20150513005929.GE14292@cloud> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150513005929.GE14292@cloud> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15051313-0033-0000-0000-0000047FA2C5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 12, 2015 at 05:59:29PM -0700, josh@joshtriplett.org wrote: > On Tue, May 12, 2015 at 03:49:12PM -0700, Paul E. McKenney wrote: > > From: "Paul E. McKenney" > > > > Reported-by: "Ahmed, Iftekhar" > > Signed-off-by: Paul E. McKenney > > Could you elaborate a bit more on this patch (ideally in its commit > message)? I see an addition of a command-line parameter to test rcu_bh; > is rcu-sched already tested elsewhere by some other config, or does this > parameter somehow enable testing both? The commit log now reads as follows, does that help? Thanx, Paul ------------------------------------------------------------------------ rcutorture: Test both RCU-sched and RCU-bh for Tiny RCU Tiny RCU supports both RCU-sched and RCU-bh, but only RCU-sched is currently tested by the rcutorture scripts. This commit therefore changes the TINY02 configuration to test RCU-bh, with TINY01 continuing to test RCU-sched. This shortcoming of the current rcutorture tests was located by mutation testing by Iftekhar. The idea behind mutation testing is to automatically mutate the code under test. If a given mutant is not caught by testing, this is a hint that the testing might need to be improved, as was the case here. Note that this is only a hint because it is possible to mutate the code into something else that still works. For example, a mutation that removes (say) a WARN_ON() will not normally result in a test failure. This change resulted in the test failure caused by list mishandling, which is fixed by the next commit. Reported-by: "Ahmed, Iftekhar" Signed-off-by: Paul E. McKenney