[CRIU] [PATCH] docs: start documenting lazy-pages

[Andrei Vagin]

Applied, thanks
On Mon, May 01, 2017 at 10:11:56AM +0300, Mike Rapoport wrote:
> Signed-off-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
> ---
>  Documentation/criu.txt | 29 +++++++++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
> 
> diff --git a/Documentation/criu.txt b/Documentation/criu.txt
> index 0a2f65b..6758e9b 100644
> --- a/Documentation/criu.txt
> +++ b/Documentation/criu.txt
> @@ -322,6 +322,15 @@ For example, the command line for the above example should look like this:
>      restore. In addition to not dumping memory pages, the checkpointed process
>      will continue running.
>  
> +*--lazy-pages*::
> +    Perform the dump procedure without writing memory pages into the
> +    image files and prepare to service page requests over the
> +    network. When *dump* runs in this mode it presumes that
> +    *lazy-pages* daemon will connect to it and fetch memory pages to
> +    lazily inject them into the restored process address space. This
> +    option is intended for post-copy (lazy) migration and should be
> +    used in conjunction with *restore* with appropriate options.
> +
>  *restore*
>  ~~~~~~~~~
>  Restores previously checkpointed processes.
> @@ -483,6 +492,14 @@ are not adequate, but this can be suppressed by using *--cpu-cap=none*.
>     to restore on an older kernel, or a kernel configured without some
>     options.
>  
> +*--lazy-pages*::
> +   Restore the processes without filling out the entire memory
> +   contents. When this option is used, *restore* sets up the
> +   infrastucture required to fill memory pages either on demand when
> +   the process accesses them or in the background without stopping the
> +   restored process.
> +   This option requires running *lazy-pages* daemon.
> +
>  *check*
>  ~~~~~~~
>  Checks whether the kernel supports the features needed by *criu* to
> @@ -549,6 +566,18 @@ Launches *criu* in page server mode.
>  *--port* 'number'::
>      Page server port number.
>  
> +*lazy-pages*
> +~~~~~~~~~~~~
> +Launches *criu* in lazy-pages daemon mode.
> +
> +The *lazy-pages* daemon is responsible for managing user-level demand
> +paging for the restored processes. It gets information required to
> +fill the process memory pages from the *restore* and from the
> +checkpont directory. When a restored process access certain memory
> +page for the first time, the *lazy-pages* daemon injects its contents
> +into the process address space. The memory pages that are not yet
> +requested by the restored processes are injected in the background.
> +
>  *exec*
>  ~~~~~~
>  Executes a system call inside a destination task\'s context. This functionality
> -- 
> 1.9.1
>