Re: [dpdk-dev] [PATCH 2/2] fib: announce experimental tag removal of the fib API

["Medvedkin, Vladimir" <vladimir.medvedkin@intel.com>]

On 05/08/2021 15:32, Jan Viktorin wrote:
> On Thu, 5 Aug 2021 15:27:15 +0200
> "Medvedkin, Vladimir" <vladimir.medvedkin@intel.com> wrote:
> 
>> Hi Jan,
>>
>> The RIB is always used as a control plane struct intended to maintain
>> the correct content of the dataplane struct, such as DIR24_8 for
>> example. So it is always used on _add()/_delete(). For simplicity you
>> can consider it as an LPM's rule_info. But instead of keeping routes
>> in a plane array as it is in LPM, FIB uses RIB which is more suitable
>> binary tree.
> 
> OK. I thought that I can have a single RIB, use it for maintaining
> routes and based on this single RIB, I can build a FIB for the data
> plane. And when the single RIB is updated (which can take quite a lot
> of time) I build a new FIB and locklessly give it to the dataplane.
> Such approach is not considered?
> 
> Jan
> 

I'm not sure I understood completely your use case. Do you want to 
rebuild the entire FIB from scratch every time the RIB changes?

>>
>>
>> On 05/08/2021 15:14, Jan Viktorin wrote:
>>> On Thu, 5 Aug 2021 15:08:13 +0200
>>> Vladimir Medvedkin <vladimir.medvedkin@intel.com> wrote:
>>>    
>>>> This patch announces the experimental tag removal of all fib APIs,
>>>> which have been experimental for 2 years.
>>>> API will be promoted to stable in DPDK 21.11
>>>
>>> Hi Vladimir,
>>>
>>> I have a question related to FIB. I am just learning how to use it
>>> and I found that each FIB always creates a new RIB internally.
>>> There is no doc about this topic...
>>>
>>> If I understand correctly, the underlying RIB is only used when
>>> dummy_lookup() and dummy_modify() are used. But they are only used
>>> when the configured mode is RTE_FIB_DUMMY. Is there any reason to
>>> create the RIB with RTE_FIB_DIR24_8?
>>>
>>> The issue with this is that each RIB allocates a new mempool
>>> internally which can waste quite a lot of never used memory that
>>> would be unused with DIR24_8 implementation.
>>>
>>> Regards
>>> Jan
>>>    
>>>>
>>>>
>>>> Signed-off-by: Vladimir Medvedkin <vladimir.medved...@intel.com>
>>>> ---
>>>>    doc/guides/rel_notes/deprecation.rst | 2 ++
>>>>    1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/doc/guides/rel_notes/deprecation.rst
>>>> b/doc/guides/rel_notes/deprecation.rst
>>>> index afb599a..58826a8 100644
>>>> --- a/doc/guides/rel_notes/deprecation.rst
>>>> +++ b/doc/guides/rel_notes/deprecation.rst
>>>> @@ -195,3 +195,5 @@ Deprecation Notices
>>>>      communicate events such as soft expiry with IPsec in lookaside
>>>> mode.
>>>>    * rib: The ``rib`` library will be promoted from experimental to
>>>> stable. +
>>>> +* fib: The ``fib`` library will be promoted from experimental to
>>>> stable.
>>
> 

-- 
Regards,
Vladimir