On Mon, Aug 26, 2019 at 05:45:55PM +0100, Ray Kinsella wrote: > > > On 23/08/2019 16:49, Aaron Conole wrote: > > Ray Kinsella <m...@ashroe.eu> writes: > > > >> This patchset adds ABI version testing to the app/test unit test framework, > >> addressing two issues previously raised during ML conversations on ABI > >> stability; > >> > >> 1. How do we unit test still supported previous ABI versions? > >> 2. How to we unit test inline functions from still supported previous ABI > >> versions? > >> > >> Starting with rte_lpm, I did the following:- > >> > >> * I reproduced mostly unmodified unit tests for the v2.0 ABI, taken from > >> DPDK > >> 2.2 and 17.02. > >> * I reproduced the rte_lpm interface header from v2.0, including the inline > >> functions and remapping symbols to their appropriate versions. > >> * I added support for multiple abi versions to the app/test unit test > >> framework > >> to allow users to switch between abi versions (set_abi_version), without > >> further polluting the already long list of unit tests available in > >> app/test. > >> > >> The intention here is that in future as developers need to deprecate APIs, > >> the > >> associated unit tests may move into the ABI version testing mechanism of > >> the > >> app/test instead of being replaced by the latest set of unit tests as > >> would be > >> the case today. > >> > >> v2: > >> > >> * Added LPM IPv6 test cases for the v2.0 ABI. > >> * Fixed a number of checkpatch errors, stop short of substantially > >> reworking > >> the test code from the v2.0 ABI. > >> * Removed duplicating test cases published in the original v1 patch. > > > > Thanks for this work. I think it's useful. > > > > I see an error under aarch64 builds because there are some x86_64 > > specific types being used in the testing. > > So the problem is that LPM didn't fully support ARM until DPDK v16.04. > The ABI versioning code in the LPM library is there to support the 2.0 ABI. > > The intention of this unit test is to test backward's compatibility with > an inline LPM function from DPDK v2.2.0, which was essentially x86 only > at that time. > > Unless we want to get into the business of backporting ARM support to > DPDK 2.2.0 (from where this test cases came from) - we should probably > restrict these ABI versioning test cases to CONFIG_RTE_ARCH_X86_64 only. > > The other option is forget about testing this the LPM ABI versioning > support, which then asks the question should be perhaps excise that code > altogether. >
I think function versioning is great and should be widely used. Unfortunately, though, in our case since we break the ABI so consistently, this old code is pretty useless. Therefore, I think we should remove all old versionned code from e.g. pre-18.11, since no app is realistically going to work from that far back anyway. /Bruce
