Re: [PATCH rdma-core RESEND] providers/rxe: Replace '%' with '&' in check_qp_queue_full()

["yangx.jy@fujitsu.com" <yangx.jy@fujitsu.com>]

On 2022/1/11 14:11, Leon Romanovsky wrote:
> On Tue, Jan 11, 2022 at 10:24:04AM +0800, Xiao Yang wrote:
>> The expression "cons == ((qp->cur_index + 1) % q->index_mask)" mistakenly
>> assumes the queue is full when the number of entires is equal to "maximum - 1"
>> (maximum is correct).
>>
>> For example:
>> If cons and qp->cur_index are 0 and q->index_mask is 1, check_qp_queue_full()
>> reports ENOSPC.
>>
>> Fixes: 1a894ca10105 ("Providers/rxe: Implement ibv_create_qp_ex verb")
>> Signed-off-by: Xiao Yang<yangx.jy@fujitsu.com>
>> ---
>>   providers/rxe/rxe_queue.h | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/providers/rxe/rxe_queue.h b/providers/rxe/rxe_queue.h
>> index 6de8140c..708e76ac 100644
>> --- a/providers/rxe/rxe_queue.h
>> +++ b/providers/rxe/rxe_queue.h
>> @@ -205,7 +205,7 @@ static inline int check_qp_queue_full(struct rxe_qp *qp)
>>   	if (qp->err)
>>   		goto err;
>>
>> -	if (cons == ((qp->cur_index + 1) % q->index_mask))
>> +	if (cons == ((qp->cur_index + 1)&  q->index_mask))
> Please reuse queue_full().
Hi Leon,

qp->cur_index and qp->err are introduced for new ibv_wr_* APIs and I am 
not sure if check_qp_queue_full() can be replaced with queue_full().

Bob, do you have any suggestion?

Best Regards,
Xiao Yang
> Thanks
>
>>   		qp->err = ENOSPC;
>>   err:
>>   	return qp->err;
>> -- 
>> 2.25.1
>>
>>
>>