Re: [PATCH] Remove process freezer from suspend to RAM pathway

Oliver Neukum
2007-07-09T09:24:17Z

Am Montag, 9. Juli 2007 schrieb Benjamin Herrenschmidt:
> On Mon, 2007-07-09 at 08:47 +0200, Oliver Neukum wrote:
> > Am Sonntag, 8. Juli 2007 schrieb Benjamin Herrenschmidt:
> > > > But I'm not sure it's a good idea in the long run.  Think of a printer
> > > > daemon, for example.  It shouldn't have to experience unexpected I/O
> > > > problems merely because someone has decided to put the system to sleep.
> > >
> > > Why not ? Printer is offline when machine is asleep... trying to print
> >
> > Not necessarily. The machine must survive going to sleep while you are
> > printing. Any other error return than -ERESTARTSYS is not an option.
> > We can't simply change the ABI.
>
> Ugh ? Why returning an error from the printer driver to the userland
> print server/daemon would prevent the machine from "surviving" ? I would
> be happy with -EIO personally :-)

Surviving is a bit strongly worded.

Suspension is to be transparent. Apart from a jump in the system clock
user space must not notice, thus returning errors due to suspension is
not an option.

Regards
Oliver