This RFC presents a new API <rte_lcore_var.h> for static per-lcore id data allocation.
Please refer to the <rte_lcore_var.h> API documentation for both a rationale for this new API, and a comparison to the alternatives available. The adoption of this API would affect many different DPDK modules, but the author updated only a few, mostly to serve as examples in this RFC, and to iron out some, but surely not all, wrinkles in the API. The question on how to best allocate static per-lcore memory has been up several times on the dev mailing list, for example in the thread on "random: use per lcore state" RFC by Stephen Hemminger. Lcore variables are surely not the answer to all your per-lcore-data needs, since it only allows for more-or-less static allocation. In the author's opinion, it does however provide a reasonably simple and clean and seemingly very much performant solution to a real problem. One thing is unclear to the author is how this API relates to potential future per-lcore dynamic allocator (e.g., a per-lcore heap). Contrary to what the version.map edit suggests, this RFC is not meant for a proposal for DPDK 24.03. Mattias Rönnblom (5): eal: add static per-lcore memory allocation facility eal: add lcore variable test suite random: keep PRNG state in lcore variable power: keep per-lcore state in lcore variable service: keep per-lcore state in lcore variable app/test/meson.build | 1 + app/test/test_lcore_var.c | 408 ++++++++++++++++++++++++++ config/rte_config.h | 1 + doc/api/doxy-api-index.md | 1 + lib/eal/common/eal_common_lcore_var.c | 82 ++++++ lib/eal/common/meson.build | 1 + lib/eal/common/rte_random.c | 30 +- lib/eal/common/rte_service.c | 119 ++++---- lib/eal/include/meson.build | 1 + lib/eal/include/rte_lcore_var.h | 374 +++++++++++++++++++++++ lib/eal/version.map | 4 + lib/power/rte_power_pmd_mgmt.c | 27 +- 12 files changed, 973 insertions(+), 76 deletions(-) create mode 100644 app/test/test_lcore_var.c create mode 100644 lib/eal/common/eal_common_lcore_var.c create mode 100644 lib/eal/include/rte_lcore_var.h -- 2.34.1
