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

Pavel Machek
2007-07-08T21:07:29Z

Hi!

> > > I just think that the freezer approach, as it is, is backward. We can't
> > > have a 3rd party try to discriminate what to freeze and what not, it
> > > will always get something wrong, and in some cases with the wrong timing
> > > or ordering.
> >
> > Nice discussion, except for one thing: the freezer doesn't decide what to
> > freeze. For example, even right now kernel threads decide if they want to be
> > frozen.
>
> Somewhat... userspace doesn't and workqueues are a gray area.

But userspace must not be neccessary for kernel functioning, so that's
quite okay. And we do need to solve the workqueues.

> Also, I've been thinking this "icebox" idea a bit more and it seems in
> fact a bit racy in some areas, at least for use by things like drivers,
> unless we end up doing something aking to an RCU on suspend, waiting for
> all tasks to reach userland once, but that has the same annoyances as
> the current freezer.
>
> Thus I'm tempted to go back to saying that driver can handle things
> locally :-)

:-). Or perhaps freezer is not _that_ evil after all?
Pavel
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