LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: "Håkon Bugge" <Haakon.Bugge@oracle.com>
To: Doug Ledford <dledford@redhat.com>,
	Don Hiatt <don.hiatt@intel.com>,
	Dasaratharaman Chandramouli
	<dasaratharaman.chandramouli@intel.com>,
	Ira Weiny <ira.weiny@intel.com>,
	Sean Hefty <sean.hefty@intel.com>
Cc: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
	"Håkon Bugge" <haakon.bugge@oracle.com>
Subject: [PATCH] IB/core: Make ib_mad_client_id atomic
Date: Wed, 18 Apr 2018 16:24:50 +0200	[thread overview]
Message-ID: <20180418142450.15581-1-Haakon.Bugge@oracle.com> (raw)

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 <haakon.bugge@oracle.com>
Reviewed-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
---
 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

             reply	other threads:[~2018-04-18 14:25 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-18 14:24 Håkon Bugge [this message]
2018-04-18 18:51 ` Weiny, Ira
2018-04-19  2:59 ` Yanjun Zhu
2018-04-20  3:55 ` Doug Ledford
2018-04-20 15:34   ` Jason Gunthorpe
2018-04-23 14:19     ` Håkon Bugge
2018-04-23 19:16       ` jackm
2018-04-26 16:06         ` Håkon Bugge
2018-04-26 18:32           ` jackm
     [not found]             ` <9fdd3ec4-ee91-5442-e753-25d2ecd27ea9@xsintricity.com>
     [not found]               ` <A58D5192-06E7-46A3-869C-273E9A2BC128@oracle.com>
2018-04-27 19:08                 ` Doug Ledford
2018-04-30 11:50                   ` Håkon Bugge
2018-04-30 14:49         ` Jason Gunthorpe
2018-04-30 17:10           ` Doug Ledford
2018-04-30 17:49             ` Weiny, Ira
2018-04-30 23:01             ` Jason Gunthorpe
2018-05-01  4:38             ` jackm
2018-05-01  6:40               ` Håkon Bugge

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180418142450.15581-1-Haakon.Bugge@oracle.com \
    --to=haakon.bugge@oracle.com \
    --cc=dasaratharaman.chandramouli@intel.com \
    --cc=dledford@redhat.com \
    --cc=don.hiatt@intel.com \
    --cc=ira.weiny@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-rdma@vger.kernel.org \
    --cc=sean.hefty@intel.com \
    --subject='Re: [PATCH] IB/core: Make ib_mad_client_id atomic' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).