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 external threads to such lcores. Those threads won't run the DPDK eal mainloop and 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 notifying of such lcore hotplug. This patchset has still some more work (like refusing new lcore type in incompatible EAL threads API, updating the documentation and adding unit tests) but I am sending it anyway as I would like to get this in for 20.08. 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 -- David Marchand David Marchand (7): 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: register non-EAL threads as lcore eal: dump lcores eal: add lcore hotplug notifications doc/guides/howto/debug_troubleshoot.rst | 5 +- lib/librte_eal/common/eal_common_lcore.c | 167 +++++++++++++++++++++- lib/librte_eal/common/eal_common_thread.c | 143 ++++++++++++++---- lib/librte_eal/common/eal_common_trace.c | 49 ++++++- lib/librte_eal/common/eal_private.h | 43 ++++++ 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 | 112 +++++++++++++-- lib/librte_eal/linux/eal.c | 17 ++- lib/librte_eal/linux/eal_thread.c | 38 +---- lib/librte_eal/rte_eal_version.map | 14 ++ lib/librte_eal/windows/eal.c | 3 +- lib/librte_eal/windows/eal_thread.c | 14 +- 16 files changed, 536 insertions(+), 162 deletions(-) -- 2.23.0
