From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751356AbdAWTaZ (ORCPT ); Mon, 23 Jan 2017 14:30:25 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:33801 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750705AbdAWTaY (ORCPT ); Mon, 23 Jan 2017 14:30:24 -0500 Date: Mon, 23 Jan 2017 11:30:16 -0800 From: "Paul E. McKenney" To: Josh Triplett Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, jiangshanlai@gmail.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 v2 tip/core/rcu 02/18] lockdep: Make RCU suspicious-access splats use pr_err Reply-To: paulmck@linux.vnet.ibm.com References: <20170118025316.GB2042@linux.vnet.ibm.com> <1484708037-2523-2-git-send-email-paulmck@linux.vnet.ibm.com> <20170121204023.im7ysfl2jdix5jox@x> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170121204023.im7ysfl2jdix5jox@x> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17012319-0028-0000-0000-000006DB3DF2 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006485; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000200; SDB=6.00811655; UDB=6.00395748; IPR=6.00589073; BA=6.00005084; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00014017; XFM=3.00000011; UTC=2017-01-23 19:30:21 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17012319-0029-0000-0000-000032F502BC Message-Id: <20170123193016.GH28085@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-01-23_15:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1701230252 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jan 21, 2017 at 12:40:23PM -0800, Josh Triplett wrote: > On Tue, Jan 17, 2017 at 06:53:41PM -0800, Paul E. McKenney wrote: > > This commit switches RCU suspicious-access splats use pr_err() > > instead of the current INFO printk()s. This change makes it easier > > to automatically classify splats. > > > > Reported-by: Dmitry Vyukov > > Signed-off-by: Paul E. McKenney > > --- > > kernel/locking/lockdep.c | 12 ++++++------ > > 1 file changed, 6 insertions(+), 6 deletions(-) > > > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > > index 7c38f8f3d97b..a74c0630172a 100644 > > --- a/kernel/locking/lockdep.c > > +++ b/kernel/locking/lockdep.c > > @@ -4412,13 +4412,13 @@ void lockdep_rcu_suspicious(const char *file, const int line, const char *s) > > #endif /* #ifdef CONFIG_PROVE_RCU_REPEATEDLY */ > > /* Note: the following can be executed concurrently, so be careful. */ > > printk("\n"); > > - printk("===============================\n"); > > - printk("[ INFO: suspicious RCU usage. ]\n"); > > + pr_err("===============================\n"); > > + pr_err("[ suspicious RCU usage. ]\n"); > > While re-adding the square bracket makes it symmetric, this change still > seems odd, and unrelated to the switch to pr_err. You could change it > to "ERR:" if you want, if "INFO:" feels inaccurate to you. So this would be OK? pr_err("[ ERR: suspicious RCU usage. ]\n"); (Changed to this as a best guess, but please let me know.) Thanx, Paul > > print_kernel_ident(); > > - printk("-------------------------------\n"); > > - printk("%s:%d %s!\n", file, line, s); > > - printk("\nother info that might help us debug this:\n\n"); > > - printk("\n%srcu_scheduler_active = %d, debug_locks = %d\n", > > + pr_err("-------------------------------\n"); > > + pr_err("%s:%d %s!\n", file, line, s); > > + pr_err("\nother info that might help us debug this:\n\n"); > > + pr_err("\n%srcu_scheduler_active = %d, debug_locks = %d\n", > > !rcu_lockdep_current_cpu_online() > > ? "RCU used illegally from offline CPU!\n" > > : !rcu_is_watching() > > -- > > 2.5.2 > > >