On Wed 2008-07-09 09:08:07, Miklos Szeredi wrote: > On Tue, 8 Jul 2008, Arjan van de Ven wrote: > > I tihnk the idea there is > > > > freeze . do the snapshot op . unfreeze . make backup of snapshot > > Ah, so then my proposal would become > > run_frozen mountpoint do-snapshot > do-backup > release-snapshot > > and if they are afraid of deadlocks they can just implement the > timeout in userspace: > > run_frozen -t timeout mountpoint do-snapshot > > 'run_frozen' can be a trivial 30 line app, that can be guaranteed not > to deadlock. Userland apps can be swapped out and need kernel memory allocations during syscalls. I bet even sleep(30) uses kmalloc internally. So yes, even trivial applications can deadlock. -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
