On Wed, Apr 15, 2015 at 9:02 AM, Bastien Nocera <bnocera(a)redhat.com> wrote:
----- Original Message -----
> On Wed, Apr 15, 2015 at 10:26:14AM -0400, Bastien Nocera wrote:
> >
> >
> > ----- Original Message -----
> > > On Tue, Apr 14, 2015 at 09:30:31AM -0600, Chris Murphy wrote:
> > > > On Tue, Apr 14, 2015 at 3:07 AM, Bastien Nocera
<bnocera(a)redhat.com>
> > > > wrote:
> > > > >
> > > > >
> > > > > ----- Original Message -----
> > > > >> OK not everyone is on the same page, apparently. This bug was
just
> > > > >> closed by Anaconda as WONTFIX.
> > > > >>
> > > > >> suggested swap for laptop seems low
> > > > >>
https://bugzilla.redhat.com/show_bug.cgi?id=1037472
> > > > >>
> > > > >> I don't see how hibernation works reliably with such a
low default
> > > > >> swap
> > > > >> size.
> > > > >
> > > > > This isn't the way to fix it. The hibernation file/partition
should
> > > > > really be independent
> > > > > of swap, because 1) you can't be sure how much swap will
actually be
> > > > > used
> > > > > by the applications
> > > > > so you can't be sure you'll ever have enough swap to save
the RAM 2)
> > > > > Too
> > > > > much swap and the
> > > > > (lack of) interactivity will make you want to advocate physical
> > > > > violence
> > > > > when your machine
> > > > > is unusable for an hour because of a hungry Javascript in your
50th
> > > > > Firefox tab.
> > > >
> > > > Windows and OS X both use swapfiles rather than swap partition, and a
> > > > sleep image file rather than a partition. OS X's swapfiles are
> > > > dynamically created on demand in variable size increments.
> > > I think the problem is in the ways filesystems are implemented. The
> > > fs has to be mounted to access the swap file, and this can change the
> > > fs, even with a read-only mount. Because we don't have
> > > really-read-only fs mounting, we need to support swap-as-partition, so
> > > we might just as well use it by default.
> > >
> > > > Both OS's have a feature that I find invaluable on a laptop which
is
> > > > the automatic switch from suspend-to-RAM to suspend-to-disk.
> > > Yes, integrating with firmware would be great. So far this hasn't been
> > > hapenning...
> > > What we can do instead is use hybrid sleep. It's not smart at all,
> > > and doesn't prevent your battery from draining completely, but it does
> > > protect
> > > your data.
> > >
> > > Systemd supports hybrid-sleep as another option analogous to suspend
> > > and hibernation, so for anything using systemd to suspend swithing to
> > > hybrid should be trivial. Maybe we should make this an F23 goal:
> > > - use hybrid-sleep from Gnome and other DE by default
> >
> > Hybrid sleep as offered in systemd still is just suspend + hibernation, and
> > the way we do hibernation is broken.
> Can you be more specific? Do you consider hibernate-to-swap-partition
> unacceptable?
I think that conflating "memory-to-disk swap space" with "I can hibernate
my machine"
is unacceptable. We need a new partition type that Anaconda would setup, or
a whitelist of laptops with firmwares that support rapid start (and again, Anaconda
to set it up), or use a temporary file of any sort to store the hibernation data.
I'm willing to bet there's an incongruence between IRST and multiboot.
If my machine has 8 gigs of memory, I don't want to need 8 gigs plus of swap to be
able to hibernate it, when run away processes can make my machine unusable for hours
if they start hitting that swap.
Googling brings up the swapspace project for dynamically creating
swapfiles. However, for Btrfs and LVM thinp installs, I think the base
swap code needs revisiting to defer rw through the fs rather than
assuming direct rw is workable.
--
Chris Murphy