Hello Dodji, On Tue, Feb 27, 2024 at 6:44 AM Tyler Retzlaff <roret...@linux.microsoft.com> wrote: > > RTE_MARKER typedefs are a GCC extension unsupported by MSVC. Remove > RTE_MARKER fields from rte_mbuf struct. > > Maintain alignment of fields after removed cacheline1 marker by placing > C11 alignas(RTE_CACHE_LINE_MIN_SIZE). > > Update implementation of rte_mbuf_prefetch_part1() and > rte_mbuf_prefetch_part2() inline functions calculate pointer for > prefetch of cachline0 and cachline1 without using removed markers. > > Update static_assert of rte_mbuf struct fields to reference data_off and > packet_type fields that occupy the original offsets of the marker > fields. > > Signed-off-by: Tyler Retzlaff <roret...@linux.microsoft.com>
This change is reported as a potential ABI change. For the context, this patch https://patchwork.dpdk.org/project/dpdk/patch/1709012499-12813-21-git-send-email-roret...@linux.microsoft.com/ removes null-sized markers (those fields were using RTE_MARKER, see https://git.dpdk.org/dpdk/tree/lib/eal/include/rte_common.h#n583) from the rte_mbuf struct. I would argue this change do not impact ABI as the layout of the mbuf object is not impacted. As reported by the CI: [C] 'function const rte_eth_rxtx_callback* rte_eth_add_first_rx_callback(uint16_t, uint16_t, rte_rx_callback_fn, void*)' at rte_ethdev.c:5768:1 has some indirect sub-type changes: parameter 3 of type 'typedef rte_rx_callback_fn' has sub-type changes: underlying type 'typedef uint16_t (typedef uint16_t, typedef uint16_t, rte_mbuf**, typedef uint16_t, typedef uint16_t, void*)*' changed: in pointed to type 'function type typedef uint16_t (typedef uint16_t, typedef uint16_t, rte_mbuf**, typedef uint16_t, typedef uint16_t, void*)': parameter 3 of type 'rte_mbuf**' has sub-type changes: in pointed to type 'rte_mbuf*': in pointed to type 'struct rte_mbuf' at rte_mbuf_core.h:470:1: type size hasn't changed 4 data member deletions: 'RTE_MARKER cacheline0', at offset 0 (in bits) at rte_mbuf_core.h:467:1 'RTE_MARKER64 rearm_data', at offset 128 (in bits) at rte_mbuf_core.h:490:1 'RTE_MARKER rx_descriptor_fields1', at offset 256 (in bits) at rte_mbuf_core.h:517:1 'RTE_MARKER cacheline1', at offset 512 (in bits) at rte_mbuf_core.h:598:1 no data member change (1 filtered); Error: ABI issue reported for abidiff --suppr /home/runner/work/dpdk/dpdk/devtools/libabigail.abignore --no-added-syms --headers-dir1 reference/usr/local/include --headers-dir2 install/usr/local/include reference/usr/local/lib/librte_ethdev.so.24.0 install/usr/local/lib/librte_ethdev.so.24.1 ABIDIFF_ABI_CHANGE, this change requires a review (abidiff flagged this as a potential issue). Opinions? Btw, I see no way to suppress this (except a global [suppress_type] name = rte_mbuf)... -- David Marchand
