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

[Miklos Szeredi]

> > 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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/