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

Miklos Szeredi
2007-07-05T08:58:17Z

> > And teach VFS to block suspension, while waiting on a mutex held by
> > another process performing a fuse operation.
> >
> > I can already hear the beautiful praise from Al Viro at the sight of
> > that ;)
>
> There is that.
>
> OK, bite the bullet. Tasks involved in fuse are special. Give them a flag
> and teach the freezer to put them on ice only after all other task are
> frozen. In a way they are kernel, there's no use denying that.

And flag every other process, that the flagged process is
communicating with? How are you proposing to do that?

Quoting Paul:

"1. The freezer cannot be guaranteed deadlock-free without constructing
a dependency graph between tasks (both user and kernel), which is
virtually impossible since the dependencies are not externally
observable."

Miklos