Re: Back to the future.

Linus Torvalds
2007-04-28T21:26:07Z

On Sat, 28 Apr 2007, Rafael J. Wysocki wrote:
> >
> > The freezer has *caused* those deadlocks (eg by stopping threads that were
> > needed for the suspend writeouts to succeed!), not solved them.
>
> I can't remember anything like this, but I believe you have a specific test
> case in mind.

Ehh.. Why do you thik we _have_ that PF_NOFREEZE thing in the first place?

Rafael, you really don't know what you're talking about, do you?

Just _look_ at them. It's the IO threads etc that shouldn't be frozen,
exactly *because* they do IO. You claim that kernel threads shouldn't do
IO, but that's the point: if you cannot do IO when snapshotting to disk,
here's a damn big clue for you: how do you think that snapshot is going to
get written?

I *guarantee* you that we've had a lot more problems with threads that
should *not* have been frozen than with those hypothetical threads that
you think should have been frozen.

Linus