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Message-ID: <b37c53a7-86df-0283-1a77-c31af108d39f@linux.alibaba.com>
Date:   Wed, 11 May 2022 11:44:07 +0800
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Subject: Re: [PATCH v2 2/2] RDMA/rxe: Generate error completion for error
 requester state
Content-Language: en-US
To:     Li Zhijian <lizhijian@fujitsu.com>,
        Zhu Yanjun <zyjzyj2000@gmail.com>,
        Jason Gunthorpe <jgg@ziepe.ca>, linux-rdma@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org
References: <20220511023030.229212-1-lizhijian@fujitsu.com>
 <20220511023030.229212-3-lizhijian@fujitsu.com>
From:   Cheng Xu <chengyou@linux.alibaba.com>
In-Reply-To: <20220511023030.229212-3-lizhijian@fujitsu.com>
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On 5/11/22 10:30 AM, Li Zhijian wrote:
> SoftRoCE always returns success when user space is posting a new wqe where
> it usually just enqueues a wqe.
> 
> Once the requester state becomes QP_STATE_ERROR, we should generate error
> completion for all subsequent wqe. So the user is able to poll the
> completion event to check if the former wqe is handled correctly.
> 
> Here we check QP_STATE_ERROR after req_next_wqe() so that the completion
> can associate with its wqe.
> 
> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
> ---
>   drivers/infiniband/sw/rxe/rxe_req.c | 10 +++++++++-
>   1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/sw/rxe/rxe_req.c b/drivers/infiniband/sw/rxe/rxe_req.c
> index 8bdd0b6b578f..ed6a486c4343 100644
> --- a/drivers/infiniband/sw/rxe/rxe_req.c
> +++ b/drivers/infiniband/sw/rxe/rxe_req.c
> @@ -624,7 +624,7 @@ int rxe_requester(void *arg)
>   	rxe_get(qp);
>   
>   next_wqe:
> -	if (unlikely(!qp->valid || qp->req.state == QP_STATE_ERROR))
> +	if (unlikely(!qp->valid))
>   		goto exit;
>   
>   	if (unlikely(qp->req.state == QP_STATE_RESET)) {
> @@ -646,6 +646,14 @@ int rxe_requester(void *arg)
>   	if (unlikely(!wqe))
>   		goto exit;
>   
> +	if (qp->req.state == QP_STATE_ERROR) {
> +		/*
> +		 * Generate an error completion so that user space is able to
> +		 * poll this completion.
> +		 */
> +		goto err;
> +	}
> +

Should this still use unlikely(...) ? Because the original judgement has
a unlikely surrounded.

Cheng Xu

>   	if (wqe->mask & WR_LOCAL_OP_MASK) {
>   		ret = rxe_do_local_ops(qp, wqe);
>   		if (unlikely(ret))