# Re: \[Intel-wired-lan\] \[PATCH net-next v5 0/7\] introduce DEFINE\_FLEX() macro

- From: Tony Nguyen \<anthony.l.nguyen@intel.com\>
- Date: 2023-09-27 18:54:03 
- List: netdev
- Page: https://ratatoskr.run/netdev/2023/09/11272897
- Thread: https://ratatoskr.run/netdev/2023/09/11271680/t.md

```text


On 9/19/2023 4:10 AM, Przemek Kitszel wrote:
> On 9/12/23 18:16, Kees Cook wrote:
>> On Tue, Sep 12, 2023 at 07:59:30AM -0400, Przemek Kitszel wrote:
>>> Add DEFINE_FLEX() macro, that helps on-stack allocation of structures
>>> with trailing flex array member.
>>> Expose __struct_size() macro which reads size of data allocated
>>> by DEFINE_FLEX().
>>>
>>> Accompany new macros introduction with actual usage,
>>> in the ice driver - hence targeting for netdev tree.
>>>
>>> Obvious benefits include simpler resulting code, less heap usage,
>>> less error checking. Less obvious is the fact that compiler has
>>> more room to optimize, and as a whole, even with more stuff on the stack,
>>> we end up with overall better (smaller) report from bloat-o-meter:
>>> add/remove: 8/6 grow/shrink: 7/18 up/down: 2211/-2270 (-59)
>>> (individual results in each patch).
>>>
>>> v5: same as v4, just not RFC
>>> v4: _Static_assert() to ensure compiletime const count param
>>> v3: tidy up 1st patch
>>> v2: Kees: reusing __struct_size() instead of doubling it as a new macro
>>>
>>> Przemek Kitszel (7):
>>>    overflow: add DEFINE_FLEX() for on-stack allocs
>>>    ice: ice_sched_remove_elems: replace 1 elem array param by u32
>>>    ice: drop two params of ice_aq_move_sched_elems()
>>>    ice: make use of DEFINE_FLEX() in ice_ddp.c
>>>    ice: make use of DEFINE_FLEX() for struct ice_aqc_add_tx_qgrp
>>>    ice: make use of DEFINE_FLEX() for struct ice_aqc_dis_txq_item
>>>    ice: make use of DEFINE_FLEX() in ice_switch.c
>>
>> Looks good to me! Feel free to pick up via netdev.
>>
>> -Kees
>>
>
> Thanks!
>
> Patchwork [1] says it's "Awaiting Upstream", which is the same for most of the "to: IWL" patches. That means it's delegated to Tony?

netdev maintainers,

As this has non-Intel changes and is marked for 'net-next', do you want to take this or prefer me to take via IWL and send as PR?

Thanks,
Tony

> By any means, minimizing "usage examples" to just ice driver makes it easy to merge via Tony's tree.
>
> [1] https://patchwork.kernel.org/project/netdevbpf/patch/20230912115937.1645707-2-przemyslaw.kitszel@intel.com/
```