Received-SPF: pass (google.com: domain of linux-kernel+bounces-82800-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Message-ID: <f8e36e04-2318-89e0-f65e-155575d52c5e@hisilicon.com>
Date: Tue, 27 Feb 2024 15:28:01 +0800
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Thunderbird/102.1.0
Subject: Re: [PATCH v2 for-next 2/2] RDMA/hns: Support userspace configuring
 congestion control algorithm with QP granularity
To: Jason Gunthorpe <jgg@ziepe.ca>
CC: <leon@kernel.org>, <linux-rdma@vger.kernel.org>, <linuxarm@huawei.com>,
	<linux-kernel@vger.kernel.org>
References: <20240208035038.94668-1-huangjunxian6@hisilicon.com>
 <20240208035038.94668-3-huangjunxian6@hisilicon.com>
 <20240221155248.GD13491@ziepe.ca>
 <26ea175c-fa31-720c-2ac3-41abcb4d398a@hisilicon.com>
 <20240226140647.GB3220539@ziepe.ca>
Content-Language: en-US
From: Junxian Huang <huangjunxian6@hisilicon.com>
In-Reply-To: <20240226140647.GB3220539@ziepe.ca>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 7bit

Problems below will be fixed in next version.

Thanks,
Junxian

On 2024/2/26 22:06, Jason Gunthorpe wrote:
> On Thu, Feb 22, 2024 at 03:06:20PM +0800, Junxian Huang wrote:
>>>> +enum hns_roce_congest_type_flags {
>>>> +	HNS_ROCE_CREATE_QP_FLAGS_DCQCN = 1 << 0,
>>>> +	HNS_ROCE_CREATE_QP_FLAGS_LDCP = 1 << 1,
>>>> +	HNS_ROCE_CREATE_QP_FLAGS_HC3 = 1 << 2,
>>>> +	HNS_ROCE_CREATE_QP_FLAGS_DIP = 1 << 3,
>>>> +};
>>>
>>> Why are these bit flags if they are exclusive?
>>>
>>
>> Our FW uses bit flags. Although there is no direct relationship between
>> FW and ABI, but from the perspective of readability, bit flags are also
>> used consistently here in ABI.
> 
> Don't do that in uapi.
> 
>>>> +enum hns_roce_create_qp_comp_mask {
>>>> +	HNS_ROCE_CREATE_QP_MASK_CONGEST_TYPE = 1 << 1,
>>>
>>> Why 1<<1 not 1<<0?
>>
>> This is to keep consistent with our internal ABI, there are some
>> features not upstream yet.
> 
> Nope, pack them tightly. Don't keep an "internal ABI"
> 
>>>> @@ -114,6 +128,9 @@ struct hns_roce_ib_alloc_ucontext_resp {
>>>>  	__u32	reserved;
>>>>  	__u32	config;
>>>>  	__u32	max_inline_data;
>>>> +	__u8	reserved0;
>>>> +	__u8	congest_type;
>>>
>>> Why this layout?
>>
>> Same as the 1<<1 issue, to keep consistent with our internal ABI.
> 
> Same answer
> 
> Jason