From: Doug Ledford <dledford@redhat.com>
To: Bart Van Assche <bart.vanassche@wdc.com>,
Jason Gunthorpe <jgg@mellanox.com>
Cc: linux-rdma@vger.kernel.org, Moni Shoua <monis@mellanox.com>,
stable@vger.kernel.org
Subject: Re: [PATCH] RDMA/rxe: Fix a race condition related to the QP error state
Date: Wed, 10 Jan 2018 16:40:34 -0500 [thread overview]
Message-ID: <1515620434.3403.169.camel@redhat.com> (raw)
In-Reply-To: <20180109192340.25702-1-bart.vanassche@wdc.com>
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On Tue, 2018-01-09 at 11:23 -0800, Bart Van Assche wrote:
> The following sequence:
> * Change queue pair state into IB_QPS_ERR.
> * Post a work request on the queue pair.
> Triggers the following race condition in the rdma_rxe driver:
> * rxe_qp_error() triggers an asynchronous call of rxe_completer(), the function
> that examines the QP send queue.
> * rxe_post_send() posts a work request on the QP send queue.
If rxe_completer() runs before rxe_post_send(), the send queue is
believed to be empty while a stale work request stays on the send queue
indefinitely. To avoid this race, schedule rxe_completer() after a work
request is queued on a qp in the error state by rxe_post_send().
I think that improves the log message, yes?
--
Doug Ledford <dledford@redhat.com>
GPG KeyID: B826A3330E572FDD
Key fingerprint = AE6B 1BDA 122B 23B4 265B 1274 B826 A333 0E57 2FDD
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next prev parent reply other threads:[~2018-01-10 21:40 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-09 19:23 [PATCH] RDMA/rxe: Fix a race condition related to the QP error state Bart Van Assche
2018-01-10 21:40 ` Doug Ledford [this message]
2018-01-10 22:01 ` Doug Ledford
2018-01-11 6:22 ` Leon Romanovsky
[not found] ` <20180111062252.GP7368-U/DQcQFIOTAAJjI8aNfphQ@public.gmane.org>
2018-01-11 16:02 ` Bart Van Assche
[not found] ` <1515686552.2752.2.camel-Sjgp3cTcYWE@public.gmane.org>
2018-01-11 19:00 ` Leon Romanovsky
2018-01-11 19:07 ` Bart Van Assche
2018-01-12 6:23 ` Leon Romanovsky
[not found] ` <20180112062359.GG15760-U/DQcQFIOTAAJjI8aNfphQ@public.gmane.org>
2018-01-12 6:32 ` Bart Van Assche
2018-01-12 6:38 ` Leon Romanovsky
2018-01-11 11:27 ` Moni Shoua
2018-01-11 16:16 ` Bart Van Assche
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