Re: [PATCH -mm] swsusp: userland interface

[Andrew Morton <akpm@osdl.org>]

"Rafael J. Wysocki" <rjw@sisk.pl> wrote:
>
> Hi,
> 
> This patch introduces a user space interface for swsusp.
> 
> The interface is based on a special character device, called the snapshot
> device, that allows user space processes to perform suspend and
> resume-related operations with the help of some ioctls and the read()/write()
> functions.  Additionally it allows these processes to allocate free swap pages
> from a selected swap partition, called the resume partition, so that they know
> which sectors of the resume partition are available to them.
> 
> The interface uses the same low-level system memory snapshot-handling
> functions that are used by the built-it swap-writing/reading code of swsusp.

The identifiers and terminology are pretty similar to dm-snap.c.  But I
don't see any clashes there.  Yet.

> The interface documentation is included in the patch.
> 
> The patch assumes that the major and minor numbers of the snapshot device
> will be 10 (ie. misc device) and 231, the registration of which has already been
> requested.

Why does it need a statically-allocated major and minor?  misc_register()
will generate a uevent and the device node should just appear...