Re: [dpdk-dev] [PATCH 0/7] Register external threads as lcore

[Jerin Jacob <jerinjacobk@gmail.com>]

On Wed, Jun 10, 2020 at 8:15 PM David Marchand
<david.marchand@redhat.com> wrote:
>
> 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.

Cool feature.

Is mempool's lcore local cache working for external cores with this scheme?


>
> 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

Usage is clear from the example code,
Looking forward to having documentation and UT for the new API
in the next version.



>
> --
> 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
>