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

Alan Stern
2007-07-03T16:03:41Z

On Tue, 3 Jul 2007, Matthew Garrett wrote:

> Suspend to RAM on a machine with / on a fuse filesystem turns out to be
> a screaming nightmare - either the suspend fails because syslog (for
> instance) can't be frozen, or the machine deadlocks for some other
> reason I haven't tracked down. We could "fix" fuse, or alternatively we
> could do what we do for suspend to RAM on other platforms (PPC and APM)
> and just not use the freezer.

Quite apart from the sync() matter, _any_ synchronous call to a FUSE
filesystem during STR will cause trouble. Even if the user task
implementing the filesystem isn't frozen, when it tries to carry out
some I/O to a suspended device it will either:

block until the system wakes up, or

cause the suspend to abort.

Neither outcome is desirable.

Alan Stern