On Mon, 2008-03-10 at 01:19 +0000, Samuel Thibault wrote: > > This thread is syncing everything, i.e. asking a lot of writes, which > triggers the creation of a lot of threads. Unfortunately the superblock > was paged out, so they all block on reading it. Unfortunately, since in > Debian there is a patch which limits the number of created threads, > the read of the superblock doesn't actually create a new thread, that is > delayed. But since none of the existing threads can progress (since > they are all waiting for the super block), things are just dead > locked...
As a general rule, the Hurd always assumes that an RPC can be handled; this is quite emebedded in the way diskfs works. A patch which limits the number of threads is inherently buggy in the Hurd, and that patch MUST be disabled for anything to work properly. > I'm currently using a quite ugly patch (on top of the >2GB patch) to > avoid this by just always keeping a copy of the superblock, attached. > I'll commit it in the Debian package. This is not a fix. This just postpones the problem. There are many pagers, all of which must always be able to function. Thomas
