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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 30364C43381 for ; Mon, 25 Feb 2019 21:10:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 05E8B20842 for ; Mon, 25 Feb 2019 21:10:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728176AbfBYVKi (ORCPT ); Mon, 25 Feb 2019 16:10:38 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:59100 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727579AbfBYVKh (ORCPT ); Mon, 25 Feb 2019 16:10:37 -0500 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1PL51Sa096482 for ; Mon, 25 Feb 2019 16:10:36 -0500 Received: from e15.ny.us.ibm.com (e15.ny.us.ibm.com [129.33.205.205]) by mx0b-001b2d01.pphosted.com with ESMTP id 2qvn9h04fk-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 25 Feb 2019 16:10:35 -0500 Received: from localhost by e15.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 25 Feb 2019 21:10:27 -0000 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp22033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x1PLAQ5717694886 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 25 Feb 2019 21:10:27 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CB115B2067; Mon, 25 Feb 2019 21:10:26 +0000 (GMT) Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A6496B205F; Mon, 25 Feb 2019 21:10:26 +0000 (GMT) Received: from paulmck-ThinkPad-W541 (unknown [9.70.82.188]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP; Mon, 25 Feb 2019 21:10:26 +0000 (GMT) Received: by paulmck-ThinkPad-W541 (Postfix, from userid 1000) id C8C2A16C1510; Mon, 25 Feb 2019 13:10:26 -0800 (PST) Date: Mon, 25 Feb 2019 13:10:26 -0800 From: "Paul E. McKenney" To: "Joel Fernandes (Google)" Cc: linux-kernel@vger.kernel.org, Alexei Starovoitov , Christian Brauner , Daniel Borkmann , David Ahern , "David S. Miller" , Ingo Molnar , Jakub Kicinski , Jeff Kirsher , Jesper Dangaard Brouer , John Fastabend , Josh Triplett , keescook@chromium.org, kernel-hardening@lists.openwall.com, kernel-team@android.com, Kirill Tkhai , Lai Jiangshan , Martin KaFai Lau , Mathieu Desnoyers , netdev@vger.kernel.org, Peter Zijlstra , Quentin Perret , rcu@vger.kernel.org, Song Liu , Steven Rostedt , Vincent Guittot , xdp-newbies@vger.kernel.org, Yonghong Song Subject: Re: [PATCH v2 3/6] sched/cpufreq: Annotate cpufreq_update_util_data pointer with __rcu Reply-To: paulmck@linux.ibm.com References: <20190223063434.6793-1-joel@joelfernandes.org> <20190223063434.6793-4-joel@joelfernandes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190223063434.6793-4-joel@joelfernandes.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 19022521-0068-0000-0000-0000039A2C8D X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010663; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000281; SDB=6.01166317; UDB=6.00609217; IPR=6.00946920; MB=3.00025738; MTD=3.00000008; XFM=3.00000015; UTC=2019-02-25 21:10:35 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19022521-0069-0000-0000-000047A0E519 Message-Id: <20190225211026.GX4072@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-02-25_11:,, 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=8.0.1-1810050000 definitions=main-1902250151 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Feb 23, 2019 at 01:34:31AM -0500, Joel Fernandes (Google) wrote: > Recently I added an RCU annotation check to rcu_assign_pointer(). All > pointers assigned to RCU protected data are to be annotated with __rcu > inorder to be able to use rcu_assign_pointer() similar to checks in > other RCU APIs. > > This resulted in a sparse error: kernel//sched/cpufreq.c:41:9: sparse: > error: incompatible types in comparison expression (different address > spaces) > > Fix this by annotating cpufreq_update_util_data pointer with __rcu. This > will also help sparse catch any future RCU misuage bugs. > > Signed-off-by: Joel Fernandes (Google) >From an RCU perspective: Reviewed-by: Paul E. McKenney > --- > kernel/sched/cpufreq.c | 2 +- > kernel/sched/sched.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/sched/cpufreq.c b/kernel/sched/cpufreq.c > index 22bd8980f32f..e316ee7bb2e5 100644 > --- a/kernel/sched/cpufreq.c > +++ b/kernel/sched/cpufreq.c > @@ -7,7 +7,7 @@ > */ > #include "sched.h" > > -DEFINE_PER_CPU(struct update_util_data *, cpufreq_update_util_data); > +DEFINE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); > > /** > * cpufreq_add_update_util_hook - Populate the CPU's update_util_data pointer. > diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h > index d04530bf251f..2ab545d40381 100644 > --- a/kernel/sched/sched.h > +++ b/kernel/sched/sched.h > @@ -2166,7 +2166,7 @@ static inline u64 irq_time_read(int cpu) > #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ > > #ifdef CONFIG_CPU_FREQ > -DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data); > +DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); > > /** > * cpufreq_update_util - Take a note about CPU utilization changes. > -- > 2.21.0.rc0.258.g878e2cd30e-goog >