From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751604AbdLAUJP (ORCPT ); Fri, 1 Dec 2017 15:09:15 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:42080 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750968AbdLAUJN (ORCPT ); Fri, 1 Dec 2017 15:09:13 -0500 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, jiangshanlai@gmail.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, fweisbec@gmail.com, oleg@redhat.com, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 05/20] rcutorture: Preempt RCU-preempt readers more vigorously Date: Fri, 1 Dec 2017 12:08:50 -0800 X-Mailer: git-send-email 2.5.2 In-Reply-To: <20171201200819.GA25519@linux.vnet.ibm.com> References: <20171201200819.GA25519@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17120120-0036-0000-0000-00000294EAA6 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008137; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000243; SDB=6.00954005; UDB=6.00482088; IPR=6.00734080; BA=6.00005726; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00018295; XFM=3.00000015; UTC=2017-12-01 20:09:10 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17120120-0037-0000-0000-0000428BAC00 Message-Id: <1512158945-27269-5-git-send-email-paulmck@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-12-01_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 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-1712010237 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This commit attempts to make a very rare rcutorture failure happen more often by increasing the fraction of RCU-preempt read-side critical sections that are preempted. Signed-off-by: Paul E. McKenney --- kernel/rcu/rcutorture.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 61fb95612125..2e810443975d 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -316,7 +316,7 @@ static void rcu_read_delay(struct torture_random_state *rrsp) if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) udelay(shortdelay_us); if (!preempt_count() && - !(torture_random(rrsp) % (nrealreaders * 20000))) + !(torture_random(rrsp) % (nrealreaders * 500))) torture_preempt_schedule(); /* QS only if preemptible. */ } -- 2.5.2