From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752021AbeBSBEd (ORCPT ); Sun, 18 Feb 2018 20:04:33 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:54312 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751884AbeBSBEc (ORCPT ); Sun, 18 Feb 2018 20:04:32 -0500 Date: Sun, 18 Feb 2018 17:04:46 -0800 From: "Paul E. McKenney" To: Byungchul Park Cc: jiangshanlai@gmail.com, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, linux-kernel@vger.kernel.org, kernel-team@lge.com Subject: Re: [PATCH] srcu: Fix incorrect condition in srcu_funnel_exp_start() Reply-To: paulmck@linux.vnet.ibm.com References: <1518598794-26752-1-git-send-email-byungchul.park@lge.com> <20180214214245.GS3617@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 18021901-0048-0000-0000-0000023B6DAA X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008556; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000254; SDB=6.00991759; UDB=6.00503788; IPR=6.00771105; MB=3.00019625; MTD=3.00000008; XFM=3.00000015; UTC=2018-02-19 01:04:27 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18021901-0049-0000-0000-0000442DCA69 Message-Id: <20180219010446.GS3617@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-02-18_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1802190011 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Feb 19, 2018 at 08:36:30AM +0900, Byungchul Park wrote: > On 2/15/2018 6:42 AM, Paul E. McKenney wrote: > >On Wed, Feb 14, 2018 at 05:59:54PM +0900, Byungchul Park wrote: > >>We should've kept sp->srcu_gp_seq_needed_exp the furthest. But > >>it probably fails because of the incorrect condition. Fix it. > >> > >>Signed-off-by: Byungchul Park > > > >Good catch, and thank you for reviewing the SRCU code, but Ildar Ismagilov > >beat you to this one. Please see 574428dee1f3 ("rcu: Fix misprint in > >srcu_funnel_exp_start") in -rcu. > > Hi Paul, > > I'm sorry I'm late. It's been Lunar New Year holiday since last > thursday. Not a problem! > Do you mean: > > git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git > > Is this rcu's main dev-tree? It is indeed! > Thanks for replying anyway, and happy new year~ And a very happy Lunar New Year to you and yours!!! Thanx, Paul > >>--- > >> kernel/rcu/srcutree.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >>diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c > >>index d5cea81..44bc0fa 100644 > >>--- a/kernel/rcu/srcutree.c > >>+++ b/kernel/rcu/srcutree.c > >>@@ -626,7 +626,7 @@ static void srcu_funnel_exp_start(struct srcu_struct *sp, struct srcu_node *snp, > >> spin_unlock_irqrestore_rcu_node(snp, flags); > >> } > >> spin_lock_irqsave_rcu_node(sp, flags); > >>- if (!ULONG_CMP_LT(sp->srcu_gp_seq_needed_exp, s)) > >>+ if (ULONG_CMP_LT(sp->srcu_gp_seq_needed_exp, s)) > >> sp->srcu_gp_seq_needed_exp = s; > >> spin_unlock_irqrestore_rcu_node(sp, flags); > >> } > >>-- > >>1.9.1 > >> > > > > > > -- > Thanks, > Byungchul >