Re: [PATCH 2.6.24-rc8-mm1 00/15] IPC: code rewrite + new functionalities

[Pavel Machek <pavel@ucw.cz>]

Hi!

> * Patches 9 to 15 propose to add some functionalities, and thus are
> submitted here for RFC, about both the interest and their implementation.
> These functionalities are:
>     - Two new control-commands:
> 	. IPC_SETID: to change an IPC's id.
> 	. IPC_SETALL: behaves as IPC_SET, except that it also sets all time
> 	  and pid values)
>     - add a /proc/<pid>/semundo file to read and write the undo values of
> some semaphores for a given process.
> 
> 	As the namespaces and the "containers" are being integrated in the
> kernel, these functionalities may be a first step to implement  the
> checkpoint/restart of an application: in fact the existing API does not allow
> to specify or to change an ID when creating an IPC, when restarting an
> application, and the times/pids values of each IPCs are also altered. May be
> someone may find another interest about this ?
> 
> So again, comments are welcome.

Checkpoint/restart is nice, but... sysV ipc is broken by design, do we
really want to extend it?
							Pavel
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