On Mo, 24.09.18 15:45, Zbigniew Jędrzejewski-Szmek (zbyszek(a)in.waw.pl) wrote:
> > Hence, I think that Fedora kernels should really turn off
> > support entirely during compilation if there's no intention to really
> > support it. This could be done either by compiling out the whole
> > subsystem's code for it, or maybe with a kernel patch that adds a
> > kernel cmdline or so, that must be specified to enable this code in
> > the kernel.
> > For all other interfaces the kernel provides we assume that it works
> > correctly if systemd can call into it. It *is* kinda weird if the
> > hibernation APIs the kernel provides are made available but actually
> > are not assumed to work properly.
> Strongly agreed. Having systemd disable it meant that it could be enabled
> and tested without either non-standard commands (whether a kernel option,
> a special systemd command, or a GNOME non-UI option), or needing a kernel
Strongly *dis*agreed ;)
Hibernation works just fine for a lot of people, and even though it's not
nice that we can't make it work for everybody, just disabling it outright
would be significant disservice to those for whom it works and who make
use of it.
Well, I suggested that there should be some kernel cmdline option or
so to enable it if there's demand for it. i.e. if people specify
"hibernatemeharder" on the kernel cmdline then they get current
behaviour, but they are on their own if they do so...
I am just saying that when we play the game of "where to disable it by
default" and there are three contenders "GNOME", "systemd" and
"kernel", then it makes the most sense to to do so in the "kernel",
i.e. the implementor and maintainer of the actual mechanism, so that
is is comprehensively enabled or disabled, and not disabled half way
and exposed in some codepaths still but not in others.
I mean, both the GNOME and the systemd developers would be fine with
supporting hibernation in their *own* codepaths, and are pretty sure
they can make their *own* codepaths safe and supportable. The problem
is in the kernel side of things, and the assumption is that the kernel
code is not supportable and not tested enough, and hence the Fedora
kernel maintainers don't want to bless it. hence I think that's where
this should be turned off, too.
I mean, adding a kernel cmdline option to your boot isn't too hard,
and people who are technical enough to understand the implications of
hibernation and are keen to test this should have no trouble in adding
the kernel cmdline option themselves.
Lennart Poettering, Red Hat