Hi,
On 02/13/2015 03:25 AM, Zhang, Helin wrote:
>> On 02/11/2015 06:32 AM, Zhang, Helin wrote:
>>>> On 02/10/2015 07:03 AM, Zhang, Helin wrote:
>>>>>> /* Enable checksum offloading */
>>>>>> cd_tunneling_params = 0;
>>>>>> - i40e_txd_enable_checksum(ol_flags, &td_cmd, &td_offset,
>>>>>> - l2_len, l3_len,
>>>>>> outer_l2_len,
>>>>>> - outer_l3_len,
>>>>>> - &cd_tunneling_params);
>>>>>> + if (ol_flags & I40E_TX_CKSUM_OFFLOAD_MASK) {
>>>>> likely should be added.
>>>>
>>>> I would say unlikely() instead. I think the non-offload case should
>>>> be the default one. What do you think?
>>
>> Maybe you missed this comment. Any thoughts?
> Ohh, sorry for the missing!
> I'd prefer to have likely, as hardware offload is preferred if there is. If
> you
> don't think so, how about to keep nothing (no likely/unlikely) as it is.
OK, I'll use likely() as you initially suggested.
>>> As 40G is quite sensitive on cpu cycles, we'd better to avoid any
>>> performance drop during our modifying the code for fast path.
>>> Performance is what we care about too much. Based on my experiences,
>>> even minor code changes may result in big performance impact.
>>> It seems that we may need to help you on performance measurement.
>>
>> Thanks, indeed it's helpful if you can check performance non-regression.
> I have asked our validation guys here to help you on that, but might not in
> high priority. In addition, we all will take vocation for the coming Chinese
> new year.
OK, it's noted
Thanks,
Olivier
