Re: [PATCH] RDMA/RXE: Add send_common_ack() helper

["lizhijian@fujitsu.com" <lizhijian@fujitsu.com>]

On 01/08/2022 15:47, Zhu Yanjun wrote:
> On Mon, Aug 1, 2022 at 3:28 PM lizhijian@fujitsu.com
> <lizhijian@fujitsu.com> wrote:
>>
>>
>> On 01/08/2022 15:11, Zhu Yanjun wrote:
>>> On Mon, Aug 1, 2022 at 2:16 PM Li Zhijian <lizhijian@fujitsu.com> wrote:
>>>> Most code in send_ack() and send_atomic_ack() are duplicate, move them
>>>> to a new helper send_common_ack().
>>>>
>>>> In newer IBA SPEC, some opcodes require acknowledge with a zero-length read
>>>> response, with this new helper, we can easily implement it later.
>>>>
>>>> Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
>>>> ---
>>>>    drivers/infiniband/sw/rxe/rxe_resp.c | 43 ++++++++++++++----------------------
>>>>    1 file changed, 17 insertions(+), 26 deletions(-)
>>>>
>>>> diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
>>>> index b36ec5c4d5e0..4c398fa220fa 100644
>>>> --- a/drivers/infiniband/sw/rxe/rxe_resp.c
>>>> +++ b/drivers/infiniband/sw/rxe/rxe_resp.c
>>>> @@ -1028,50 +1028,41 @@ static enum resp_states do_complete(struct rxe_qp *qp,
>>>>                   return RESPST_CLEANUP;
>>>>    }
>>>>
>>>> -static int send_ack(struct rxe_qp *qp, u8 syndrome, u32 psn)
>>>> +
>>>> +static int send_common_ack(struct rxe_qp *qp, u8 syndrome, u32 psn,
>>> The function is better with rxe_send_common_ack?
>> I'm not clear the exact rule about the naming prefix. if it has, please let me know :)
>>
>> IMHO, if a function is either a public API(export function) or a callback to a upper layer,  it's a good idea to a fixed prefix.
>> Instead, if they are just static, no prefix is not too bad.
> When debug, a rxe_ prefix can help us filter the functions whatever
> the function static or public.
>
>> BTW, current RXE are mixing the two rules, it should be another standalone patch to do the cleanup if needed.
> Yes. Please make this standalone patch to complete this.

i tried to do a rough statistic.

all functions:
$ git grep -E '^[a-z].*\(' drivers/infiniband/sw/rxe | awk -F'(' '{print $1}' | awk '{print $NF}' | tr -d '\*' | grep -E ^[a-z]+ | wc -l
474

without rxe_ prefix:
git grep -E '^[a-z].*\(' drivers/infiniband/sw/rxe | awk -F'(' '{print $1}' | awk '{print $NF}' | tr -d '\*' | grep -E ^[a-z]+ | grep -v -e ^rxe | wc -l
199

Similarly, the mlx5 have the same situations.
$ git grep -h -E '^[a-z].*\(' drivers/infiniband/hw/mlx5 | awk -F'(' '{print $1}' | awk '{print $NF}' | tr -d '\*' | grep -E ^[a-z]+ | wc -l
1083
$ git grep -h -E '^[a-z].*\(' drivers/infiniband/hw/mlx5 | awk -F'(' '{print $1}' | awk '{print $NF}' | tr -d '\*' | grep -E ^[a-z]+ | grep -v -e ^mlx5 | wc -l
476

TBH, i have no strong stomach to do such cleanup so far :)

Thanks
Zhijian


>
> Thanks and Regards,
> Zhu Yanjun
>
>> Thanks
>> Zhijian
>>
>>
>>> So when debug, rxe_ prefix can help us.
>>>
>>>> +                                 int opcode, const char *msg)
>>>>    {
>>>> -       int err = 0;
>>>> +       int err;
>>>>           struct rxe_pkt_info ack_pkt;
>>>>           struct sk_buff *skb;
>>>>
>>>> -       skb = prepare_ack_packet(qp, &ack_pkt, IB_OPCODE_RC_ACKNOWLEDGE,
>>>> -                                0, psn, syndrome);
>>>> -       if (!skb) {
>>>> -               err = -ENOMEM;
>>>> -               goto err1;
>>>> -       }
>>>> +       skb = prepare_ack_packet(qp, &ack_pkt, opcode, 0, psn, syndrome);
>>>> +       if (!skb)
>>>> +               return -ENOMEM;
>>>>
>>>>           err = rxe_xmit_packet(qp, &ack_pkt, skb);
>>>>           if (err)
>>>> -               pr_err_ratelimited("Failed sending ack\n");
>>>> +               pr_err_ratelimited("Failed sending %s\n", msg);
>>>>
>>>> -err1:
>>>>           return err;
>>>>    }
>>>>
>>>> -static int send_atomic_ack(struct rxe_qp *qp, u8 syndrome, u32 psn)
>>>> +static int send_ack(struct rxe_qp *qp, u8 syndrome, u32 psn)
>>> rxe_send_ack
>>>
>>>>    {
>>>> -       int err = 0;
>>>> -       struct rxe_pkt_info ack_pkt;
>>>> -       struct sk_buff *skb;
>>>> -
>>>> -       skb = prepare_ack_packet(qp, &ack_pkt, IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE,
>>>> -                                0, psn, syndrome);
>>>> -       if (!skb) {
>>>> -               err = -ENOMEM;
>>>> -               goto out;
>>>> -       }
>>>> +       return send_common_ack(qp, syndrome, psn,
>>>> +                       IB_OPCODE_RC_ACKNOWLEDGE, "ACK");
>>>> +}
>>>>
>>>> -       err = rxe_xmit_packet(qp, &ack_pkt, skb);
>>>> -       if (err)
>>>> -               pr_err_ratelimited("Failed sending atomic ack\n");
>>>> +static int send_atomic_ack(struct rxe_qp *qp, u8 syndrome, u32 psn)
>>> rxe_send_atomic_ack
>>>
>>> Thanks and Regards,
>>> Zhu Yanjun
>>>> +{
>>>> +       int ret = send_common_ack(qp, syndrome, psn,
>>>> +                       IB_OPCODE_RC_ATOMIC_ACKNOWLEDGE, "ATOMIC ACK");
>>>>
>>>>           /* have to clear this since it is used to trigger
>>>>            * long read replies
>>>>            */
>>>>           qp->resp.res = NULL;
>>>> -out:
>>>> -       return err;
>>>> +       return ret;
>>>>    }
>>>>
>>>>    static enum resp_states acknowledge(struct rxe_qp *qp,
>>>> --
>>>> 1.8.3.1
>>>>