[Devel] Re: [PATCH 4/4] Add some content to the readme.txt for socket c/r

[Oren Laadan]

Dan Smith wrote:
> Signed-off-by: Dan Smith <danms at us.ibm.com>

Nicely put !

> ---
>  Documentation/checkpoint/readme.txt |   21 +++++++++++++++++++++
>  1 files changed, 21 insertions(+), 0 deletions(-)
> 
> diff --git a/Documentation/checkpoint/readme.txt b/Documentation/checkpoint/readme.txt
> index 571c469..e6c173d 100644
> --- a/Documentation/checkpoint/readme.txt
> +++ b/Documentation/checkpoint/readme.txt
> @@ -334,6 +334,27 @@ we will be forced to more carefully review each of those features.
>  However, this can be controlled with a sysctl-variable.
>  
>  
> +Sockets
> +=======
> +
> +For AF_UNIX sockets, both endpoints must be within the checkpointed
> +task set to maintain a connected state after restart.  UNIX sockets
> +that are in the process of passing a descriptor will cause the
> +checkpoint to fail with -EBUSY indicating a transient state that
> +cannot be checkpointed.  Listening sockets with an unaccepted peer
> +will also cause an -EBUSY result.
> +
> +AF_INET sockets with endpoints outside the checkpointed task set may
> +remain open if care is taken to avoid TCP timeouts and resets.
> +Careful use of a virtual IP address can help avoid emission of an RST
> +to the non-checkpointed endpoint.  If desired, the
> +RESTART_SOCK_LISTENONLY flag may be passed to the restart syscall
> +which will cause all connected AF_INET sockets to be closed during the
> +restore process.  Listening sockets will still be restored to their
> +original state, which makes this mode a candidate for something like
> +an HTTP server.
> +
> +
>  Kernel interfaces
>  =================
>  
_______________________________________________
Containers mailing list
Containers at lists.linux-foundation.org
https://lists.linux-foundation.org/mailman/listinfo/containers