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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 7E66DC3B1A6 for ; Fri, 14 Feb 2020 17:26:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5B73124650 for ; Fri, 14 Feb 2020 17:26:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391178AbgBNR0i (ORCPT ); Fri, 14 Feb 2020 12:26:38 -0500 Received: from mga09.intel.com ([134.134.136.24]:40382 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390996AbgBNR0i (ORCPT ); Fri, 14 Feb 2020 12:26:38 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Feb 2020 09:26:37 -0800 X-IronPort-AV: E=Sophos;i="5.70,441,1574150400"; d="scan'208";a="223081578" Received: from ddalessa-mobl.amr.corp.intel.com (HELO [10.254.204.146]) ([10.254.204.146]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 14 Feb 2020 09:26:35 -0800 Subject: Re: [PATCH 3/3] infiniband: sw: rdmavt: mcast.c: Use built-in RCU list checking To: madhuparnabhowmik04@gmail.com, mike.marciniszyn@intel.com, jgg@ziepe.ca, paulmck@kernel.org Cc: joel@joelfernandes.org, frextrite@gmail.com, linux-kernel-mentees@lists.linuxfoundation.org, rcu@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org References: <20200114162536.20388-1-madhuparnabhowmik04@gmail.com> From: Dennis Dalessandro Message-ID: Date: Fri, 14 Feb 2020 12:26:34 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.4.2 MIME-Version: 1.0 In-Reply-To: <20200114162536.20388-1-madhuparnabhowmik04@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: rcu-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org On 1/14/2020 11:25 AM, madhuparnabhowmik04@gmail.com wrote: > From: Madhuparna Bhowmik > > Use built-in RCU and lock-checking for list_for_each_entry_rcu() > by passing the cond argument. > > Signed-off-by: Madhuparna Bhowmik > --- > drivers/infiniband/sw/rdmavt/mcast.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/infiniband/sw/rdmavt/mcast.c b/drivers/infiniband/sw/rdmavt/mcast.c > index dd11c6fcd060..31c7f12c7665 100644 > --- a/drivers/infiniband/sw/rdmavt/mcast.c > +++ b/drivers/infiniband/sw/rdmavt/mcast.c > @@ -224,7 +224,7 @@ static int rvt_mcast_add(struct rvt_dev_info *rdi, struct rvt_ibport *ibp, > } > > /* Search the QP list to see if this is already there. */ > - list_for_each_entry_rcu(p, &tmcast->qp_list, list) { > + list_for_each_entry_rcu(p, &tmcast->qp_list, list, lockdep_is_held(&(ibp->lock))) { > if (p->qp == mqp->qp) { > ret = ESRCH; > goto bail; > This one is OK. The lock is held and it is the correct one to use when updating the list. Reviewed-by: Dennis Dalessandro