Re: [dpdk-dev] [PATCH v2 0/3] introduce global debug flag

[Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>]

W dniu 24.04.2020 o 11:09, Bruce Richardson pisze:
> On Wed, Apr 22, 2020 at 11:45:52PM +0200, Lukasz Wojciechowski wrote:
>> This set of patches introduces a global rte_debug flag for dpdk.
>> This will allow easy switch to debug build configuration using a single
>> flag. In the debug mode a RTE_DEBUG macro is defined to 1
>> and for every enabled to be built librarte a RTE_DEBUG_{library name}
>> is also defined. These macros can be used to place a debug code
>> inside #ifdef #endif clauses.
>>
>> The following requirements were discussed on the mailing list:
>> 1) The global debug flag is required to enable all the sanity checks
>> and validations that are normally not used due to performance reasons
>>
>> 2) The best option would be to have a single flag - not to introduce
>> too many build options
>>
>> 3) This option should be separated from meson "debug" option
>> (used for build with symbols) and can be called "rte_debug"
>>
>> 4) The currently existing DEBUG macros should not be replaced with
>> a RTE_DEBUG macro. This would allow to still enable them using
>> CFLAGS="-D..." to test a single module (library, driver).
>>
>> 5) Currently existing options' names should be standardized
>> to RTE_DEBUG_{library/driver name}, so they can be automatically enabled
>> when rte_debug is set. Standardized names would allow easy usage
>> in other modules.
>>
>> 6) The debug functionality should be encapsulated in:
>>          if (rte_log_can_log(...)) {
>>                  ...
>>          }
>> for possibility to be filtered out in runtime.
>>
>>
>> Because of the hot discussion of v1 version of patches, I limit
>> the v2 version to mbuf library changes only, to see how it will impact
>> the performance with rte_log_can_log usage and to get opinions.
>>
>> Next steps would be to follow changes in other libraries and drivers.
>>
>> ---
>> v2:
>> * Use new meson option rte_debug instead of debug
>> * Add standardized defines for built libraries
>> * Limit patches to mbuf library (as a POC)
>> * Use rte_log_can_log to wrap debug section
>>
>> Lukasz Wojciechowski (3):
>>    config: introduce global rte debug flag
>>    config: remove unused config flags
>>    mbuf: standardize library debug flag
>>
> I really like this set, looks a good approach to me anyway.
>
> Out of interest - did you automate the scanning for all the different build
> flags to find those in the second patch that weren't used, or did you come
> across them by chance? Just wondering if there are any other unused flags
> we can remove.
I've done this semi-automated way. Just some greping and seding, but I 
focused  only on debug flags, so there might be more other flags.

-- 

Lukasz Wojciechowski
Principal Software Engineer

Samsung R&D Institute Poland
Samsung Electronics
Office +48 22 377 88 25
l.wojciechow@partner.samsung.com