Re: Back to the future.

Daniel Hazelton
2007-04-28T02:52:12Z

On Friday 27 April 2007 21:44:48 Rafael J. Wysocki wrote:
> On Saturday, 28 April 2007 03:12, Linus Torvalds wrote:
> > On Sat, 28 Apr 2007, Rafael J. Wysocki wrote:
> > > > It's doubly bad, because that idiocy has also infected s2ram. Again,
> > > > another thing that really makes no sense at all - and we do it not
> > > > just for snapshotting, but for s2ram too. Can you tell me *why*?
> > >
> > > Why we freeze tasks at all or why we freeze kernel threads?
> >
> > In many ways, "at all".
> >
> > I _do_ realize the IO request queue issues, and that we cannot actually
> > do s2ram with some devices in the middle of a DMA. So we want to be able
> > to avoid *that*, there's no question about that. And I suspect that
> > stopping user threads and then waiting for a sync is practically one of
> > the easier ways to do so.
> >
<snip>

Apparently I *CANNOT* wrap my head around this - if just because my laptop,
running a vendor 2.6.17 kernel does s2ram perfectly, at least, it does when
using the "Upstart" init system rather than the classical SysV init system. I
have tried it with the classical init and the suspend isn't triggered by the
buttons that used to do it. I didn't try 'echo ram > /sys/power/state', but I
have a feeling that would have worked as well. I have problems with s2disk,
but thats because I keep my swap partition small - I try to keep it at or
around 256M when I have more than half a gig of Ram in a system. Perhaps one
of these days I'll grab a multi-gig flash disk, set it up as a swap partition
and try it again. (every time I've tried s2disk I wind up running out of disk
space - and this is with nothing but X running. Any kind of progress meter
for when the system is doing s2disk would be nice - every time I've tried it
all I see for the nearly 2 minutes before the s2disk attempt ends is a black
screen. I say 2 minutes because thats how long it takes for it to learn that
there isn't enough space on the swap-partition to save the image)

DRH