Am Donnerstag, 5. Juli 2007 schrieb Pavel Machek: > On Tue 2007-07-03 19:20:59, Oliver Neukum wrote: > > Am Dienstag, 3. Juli 2007 schrieb Rafael J. Wysocki: > > > On Tuesday, 3 July 2007 15:08, Rafael J. Wysocki wrote: > > > > On Tuesday, 3 July 2007 07:51, Benjamin Herrenschmidt wrote: > > > > > On Tue, 2007-07-03 at 05:29 +0100, 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. > > > > > > > > > > The main reason for deadlocks is because we do a sys_sync() after the > > > > > freeze, which we shouldn't do. > > > > > > > > So why don't we remove the sys_sync() from freeze_processes() instead? > > > > > > The patch follows (untested). > > > > > > Greetings, > > > Rafael > > > > > > > > > --- > > > From: Rafael J. Wysocki <rjw@xxxxxxx> > > > > > > We shouldn't sync filesystems from within the freezer, because it's not needed > > > for suspend to RAM and leads to problems with FUSE. > > > > This seems fishy. Swsusp needs enough clean memory to make enough > > room for the image. If you sync before you freeze, the running tasks can > > redirty memory. > > What makes you sure that you don't die as shrink_all_memory() writes out > > pages? > > Shrink_all_memory should just free enough memory, what's the problem? > Yes, we can have dirty memory, shrink_all_memory() can write that out > just fine. If there's any dirty memory to be written out through fuse, this will not work as user space is already frozen. Now I am told that with fuse writes are synchronous. Therefore I don't understand why having a call to sys_sync() can make a difference. IMHO removing it to make fuse work covers over a symptom but hides the bug. Regards Oliver _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
