Re: [PATCH v4 0/2] generic channel for multi-process communication

["Tan, Jianfeng" <jianfeng.tan@intel.com>]

Apology, please ignore this version which is not correct. Will send out 
a new version.


On 1/26/2018 3:14 AM, Jianfeng Tan wrote:
> v3->v4:
>    - Drop the patch 3 on vfio communication (postponed).
>    - Change names from rte_eal_mp_* -> rte_mp_* as suggested by Thomas.
>    - Add nb_sent and nb_received in struct rte_mp_reply.
>    - Standardize the return val of sendmsg, request, reply: 0 on sucess,
>      (-1) on failure.
>    - If we found an peer error when we send msg in primary, we try to
>      remove the secondary socket; as there is no sync mechanism there
>      (cannot do flock like regular file for socket file), we use a more
>      complex socket name (with tsc in it).
>    - Some other small changes.
>
> v2->v3:
>    - Add pre-check for each APIs.
>    - Remove the limitation of 8 secondary processes by: discard original
>      register/unregister mechanism of secondary process, instead, primary
>      discoveries secondary processes by looking up the folder for regex match.
>    - Previous implementation use two sockets for msg and request, this version
>      just uses one socket. And receive all kinds of messages in mp thread.
>
> v1->v2: (Address comments from Anatoly and Konstantin)
>    - Use datagram unix socket to supersede stream unix socket + epoll.
>    - Change the secondary add/del mechanism as now we use connection-less channel.
>    - Add mp_mutex_action to sync action register/unregister/reference.
>    - Limit max length of action name to 64B.
>    - New APIs for synchronous communication: rte_eal_mp_request/rte_eal_mp_reply.
>    - Formalize the errno handle.
>    - Some other small issues.
>
> This patchset adds a generic channel for multi-process (primary/secondary)
> communication.
>
> Patch 1: addess the purpose and howto;
> Patch 2: add a syncrhonous way for the requests which need a immediate response.
>
> Jianfeng Tan (2):
>    eal: add synchronous multi-process communication
>    vfio: use the generic multi-process channel
>
>   doc/guides/rel_notes/release_18_02.rst         |   2 +
>   lib/librte_eal/common/eal_common_proc.c        | 254 +++++++++++++--
>   lib/librte_eal/common/include/rte_eal.h        |  58 +++-
>   lib/librte_eal/linuxapp/eal/eal.c              |  14 +-
>   lib/librte_eal/linuxapp/eal/eal_vfio.c         | 169 ++++------
>   lib/librte_eal/linuxapp/eal/eal_vfio.h         |  15 +-
>   lib/librte_eal/linuxapp/eal/eal_vfio_mp_sync.c | 410 ++++---------------------
>   lib/librte_eal/rte_eal_version.map             |   2 +
>   8 files changed, 429 insertions(+), 495 deletions(-)
>