From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 73060C19759 for ; Thu, 1 Aug 2019 13:51:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4E4E620838 for ; Thu, 1 Aug 2019 13:51:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729739AbfHANvO (ORCPT ); Thu, 1 Aug 2019 09:51:14 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:49604 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725930AbfHANvN (ORCPT ); Thu, 1 Aug 2019 09:51:13 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x71DcHYt071709; Thu, 1 Aug 2019 09:51:05 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 2u40xq9527-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 01 Aug 2019 09:51:05 -0400 Received: from m0098399.ppops.net (m0098399.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.27/8.16.0.27) with SMTP id x71DcXuW072724; Thu, 1 Aug 2019 09:51:04 -0400 Received: from ppma01wdc.us.ibm.com (fd.55.37a9.ip4.static.sl-reverse.com [169.55.85.253]) by mx0a-001b2d01.pphosted.com with ESMTP id 2u40xq9515-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 01 Aug 2019 09:51:04 -0400 Received: from pps.filterd (ppma01wdc.us.ibm.com [127.0.0.1]) by ppma01wdc.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id x71DeMrq020157; Thu, 1 Aug 2019 13:51:03 GMT Received: from b01cxnp22035.gho.pok.ibm.com ([9.57.198.25]) by ppma01wdc.us.ibm.com with ESMTP id 2u0e86vvxk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 01 Aug 2019 13:51:03 +0000 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x71Dp3eT43057458 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 1 Aug 2019 13:51:03 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AED3DB206A; Thu, 1 Aug 2019 13:51:02 +0000 (GMT) Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 91097B2065; Thu, 1 Aug 2019 13:51:02 +0000 (GMT) Received: from paulmck-ThinkPad-W541 (unknown [9.70.82.154]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP; Thu, 1 Aug 2019 13:51:02 +0000 (GMT) Received: by paulmck-ThinkPad-W541 (Postfix, from userid 1000) id AF9B216C998B; Thu, 1 Aug 2019 06:51:03 -0700 (PDT) Date: Thu, 1 Aug 2019 06:51:03 -0700 From: "Paul E. McKenney" To: Peter Zijlstra Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, Juri Lelli Subject: Re: [PATCH 2/5] rcu/tree: Fix SCHED_FIFO params Message-ID: <20190801135103.GI5913@linux.ibm.com> Reply-To: paulmck@linux.ibm.com References: <20190801111348.530242235@infradead.org> <20190801111541.742613597@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190801111541.742613597@infradead.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-08-01_07:,, 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 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1906280000 definitions=main-1908010145 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 01, 2019 at 01:13:50PM +0200, Peter Zijlstra wrote: > A rather embarrasing mistake had us call sched_setscheduler() before > initializing the parameters passed to it. > > Cc: Juri Lelli > Cc: "Paul E. McKenney" Thank you for having CCed me this time. ;-) Reviewed-by: Paul E. McKenney > Fixes: 1a763fd7c633 ("rcu/tree: Call setschedule() gp ktread to SCHED_FIFO outside of atomic region") > Signed-off-by: Peter Zijlstra (Intel) > --- > kernel/rcu/tree.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -3234,13 +3234,13 @@ static int __init rcu_spawn_gp_kthread(v > t = kthread_create(rcu_gp_kthread, NULL, "%s", rcu_state.name); > if (WARN_ONCE(IS_ERR(t), "%s: Could not start grace-period kthread, OOM is now expected behavior\n", __func__)) > return 0; > - if (kthread_prio) > + if (kthread_prio) { > + sp.sched_priority = kthread_prio; > sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); > + } > rnp = rcu_get_root(); > raw_spin_lock_irqsave_rcu_node(rnp, flags); > rcu_state.gp_kthread = t; > - if (kthread_prio) > - sp.sched_priority = kthread_prio; > raw_spin_unlock_irqrestore_rcu_node(rnp, flags); > wake_up_process(t); > rcu_spawn_nocb_kthreads(); > >