OVS and some other applications have been hacking into DPDK internals to fake EAL threads and avoid performance penalty of only having non-EAL threads.
This series proposes to add a new type of lcores and maps those threads to such lcores. non-EAL threads won't run the DPDK eal mainloop. As a consequence, part of the EAL threads API cannot work. Having new lcores appearing during the process lifetime is not expected by some DPDK components. This is addressed by introducing init/uninit callacks invoked when hotplugging of such lcore. There is still some work: - refuse new lcore role in incompatible EAL threads API (or document it only as those API were already incompatible?), - finish unit tests in patch 7, - think about deprecation notices for existing RTE_FOREACH_LCORE macros and consorts, it is probably worth discussing on how to iterate over lcores, For the interested parties, I have a patch [1] against dpdk-latest OVS branch that makes use of this series. 1: https://github.com/david-marchand/ovs/commit/dpdk-latest-external-lcores Changes since v1: - rebased on master (conflicts on merged Windows series), - separated lcore role code cleanup in a patch, - tried to use a single naming, so kept non-EAL threads as the main notion. non-EAL threads are then distinguished between registered and unregistered non-EAL threads, - added unit tests (still missing some coverage, marked with a FIXME), - reworked callbacks call under a common rwlock lock which protects lcores allocations and callbacks registration, - introduced lcore iterators and converted the bucket mempool driver, -- David Marchand David Marchand (9): eal: relocate per thread symbols to common eal: fix multiple definition of per lcore thread id eal: introduce thread init helper eal: introduce thread uninit helper eal: move lcore role code eal: register non-EAL threads as lcores eal: add lcore init callbacks eal: add lcore iterators mempool/bucket: handle non-EAL lcores MAINTAINERS | 1 + app/test/Makefile | 1 + app/test/autotest_data.py | 6 + app/test/meson.build | 2 + app/test/test_lcores.c | 234 +++++++++++++++++ doc/guides/howto/debug_troubleshoot.rst | 5 +- .../prog_guide/env_abstraction_layer.rst | 22 +- doc/guides/prog_guide/mempool_lib.rst | 2 +- drivers/mempool/bucket/rte_mempool_bucket.c | 131 ++++++---- lib/librte_eal/common/eal_common_lcore.c | 241 +++++++++++++++++- lib/librte_eal/common/eal_common_thread.c | 126 ++++++--- lib/librte_eal/common/eal_common_trace.c | 49 +++- lib/librte_eal/common/eal_private.h | 19 ++ lib/librte_eal/common/eal_thread.h | 26 +- lib/librte_eal/common/eal_trace.h | 1 + lib/librte_eal/freebsd/eal.c | 16 +- lib/librte_eal/freebsd/eal_thread.c | 38 +-- lib/librte_eal/include/rte_eal.h | 12 +- lib/librte_eal/include/rte_lcore.h | 167 ++++++++++-- lib/librte_eal/linux/eal.c | 17 +- lib/librte_eal/linux/eal_thread.c | 38 +-- lib/librte_eal/rte_eal_version.map | 15 ++ lib/librte_eal/windows/eal.c | 3 +- lib/librte_eal/windows/eal_thread.c | 14 +- lib/librte_mempool/rte_mempool.h | 11 +- 25 files changed, 960 insertions(+), 237 deletions(-) create mode 100644 app/test/test_lcores.c -- 2.23.0
