Hi Nikita, I was just curious about how the tmpfs port is going. Any progress? :)
Cheers, Alex On Sat, 2009-03-28 at 22:23 +0300, Nikita Glukhov wrote: > > I think for now just use the buffer cache and get it working, even > > though that means syncing data between the buffer cache and the backing > > uobj. > > Yesterday I've got it working using buffer cache. vop_read() and vop_write() > have been stolen from HAMMER. Also I've implemented tmpfs_strategy() simply by > moving here tmpfs_mappedread() and tmpfs_mappedwrite() with some changes. > > Now there is ability to run files from tmpfs and it unmounts without deadlocks > (how it was earlier). It survives after fsstress but still has > problems with fsx - > reading bad data after truncating up. When mapped writing is used one > error sometimes happens: at vnode_pager_generic_getpages() after > VOP_READ() "page failed but no I/O error". I've became familiar with > that error when I was trying to > implement vop_getpages(). > > > > I think the way to fix this is to implement a feature in the real > > kernel that tells it that the VM object backing the vnode should > > never be cleaned (so clean pages in the object are never destroyed), > > and then instead of destroying the VM object when the vnode is > > reclaimed we simply remove the vnode association and keep the VM > > object as the backing uobj. > > Now uobj is allocated by swap_pager. Is it possible to use swap_pager object > in > the capacity of vnode's object to get swapping working or it may interfere > with > buffer cache?
