From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752809AbeDRSvh (ORCPT ); Wed, 18 Apr 2018 14:51:37 -0400 Received: from mga12.intel.com ([192.55.52.136]:47333 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752166AbeDRSvf (ORCPT ); Wed, 18 Apr 2018 14:51:35 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,466,1517904000"; d="scan'208";a="38491060" From: "Weiny, Ira" To: =?utf-8?B?SMOla29uIEJ1Z2dl?= , Doug Ledford , "Hiatt, Don" , "Dasaratharaman Chandramouli" , "Hefty, Sean" CC: "linux-rdma@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH] IB/core: Make ib_mad_client_id atomic Thread-Topic: [PATCH] IB/core: Make ib_mad_client_id atomic Thread-Index: AQHT1yEVepSwssTlDUySP6Lhu4WvI6QG3YHQ Date: Wed, 18 Apr 2018 18:51:29 +0000 Message-ID: <2807E5FD2F6FDA4886F6618EAC48510E67DF2158@CRSMSX101.amr.corp.intel.com> References: <20180418142450.15581-1-Haakon.Bugge@oracle.com> In-Reply-To: <20180418142450.15581-1-Haakon.Bugge@oracle.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiYzgzZTM0NGYtM2ZlYS00YTNlLWE0NzEtOTE2YjE5M2Q1YjU2IiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX05UIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE2LjUuOS4zIiwiVHJ1c3RlZExhYmVsSGFzaCI6IjNyVUwrV2Y2cG1KU3hqY2FYNHFVVkdyMFZxWlFCaUJreEFwcmZRV2t5TTA9In0= x-ctpclassification: CTP_NT dlp-product: dlpe-windows dlp-version: 11.0.0.116 dlp-reaction: no-action x-originating-ip: [172.18.205.10] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id w3IIphFJ025746 > > Two kernel threads may get the same value for agent.hi_tid, if the agents are > registered for different ports. As of now, this works, as the agent list is per port. > > It is however confusing and not future robust. Hence, making it atomic. > > Signed-off-by: Håkon Bugge > Reviewed-by: Jack Morgenstein Reviewed-by: Ira Weiny > --- > drivers/infiniband/core/mad.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c index > c50596f7f98a..b28452a55a08 100644 > --- a/drivers/infiniband/core/mad.c > +++ b/drivers/infiniband/core/mad.c > @@ -59,7 +59,7 @@ module_param_named(recv_queue_size, mad_recvq_size, > int, 0444); MODULE_PARM_DESC(recv_queue_size, "Size of receive queue in > number of work requests"); > > static struct list_head ib_mad_port_list; > -static u32 ib_mad_client_id = 0; > +static atomic_t ib_mad_client_id = ATOMIC_INIT(0); > > /* Port list lock */ > static DEFINE_SPINLOCK(ib_mad_port_list_lock); > @@ -377,7 +377,7 @@ struct ib_mad_agent *ib_register_mad_agent(struct > ib_device *device, > } > > spin_lock_irqsave(&port_priv->reg_lock, flags); > - mad_agent_priv->agent.hi_tid = ++ib_mad_client_id; > + mad_agent_priv->agent.hi_tid = > atomic_inc_return(&ib_mad_client_id); > > /* > * Make sure MAD registration (if supplied) > -- > 2.13.6