[dpdk-dev] [PATCH v2 01/10] build: add an option to enable LTO build

[Andrzej Ostruszka]

On 9/18/19 3:32 PM, Ray Kinsella wrote:
> this is cool, good work.
> comments below.
[...]>> +CONFIG_RTE_ENABLE_LTO=n
>> +
>>  #
>>  # Compile to share library
>>  #
>
> Why would we make this optional in this way and expand the matrix of
> different ways to build DPDK. To ask another way, why wouldn't a user
> turn on GSO.

Compilation time is much longer.  In a normal hack|fix/compile/repeat
cycle with "compile" part being simple "make" the link time might be a
bit annoying.  So I imagine keeping LTO off for the most part of the dev
cycle and then at the end when doing release/cleanup turn LTO on - to
either get release build ready or to get some set of warnings that you
address before yet another attempt to release build.  By the way - this
make config option is equivalent to meson 'b_lto' option, which by
default is off, so we have similar behaviour in both build types.

Regards
Andrzej

PS. I assumed that you've meant "LTO" not "GSO" - if not, then please
explain what you've meant.