On Friday June 16, jblunck@xxxxxxx wrote: > On Mon, Jun 05, Neil Brown wrote: > > > I understand that this is where problem is because the selected > > dentries don't stay at the end of the list very long in some > > circumstances. In particular, other filesystems' dentries get mixed > > in. > > No. The problem is that the LRU list is too long and therefore unmounting > seems to take ages. > But I cannot see that the whole LRU list needs to be scanned during unmount. The only thing that does that is shrink_dcache_sb, which is used: in do_remount_sb in __invalidate_device in a few filesystems (autofs, coda, smbfs) and not when unmounting the filesystem (despite the comment). (This is in 2.6.17-ec6-mm2). I can see that shrink_dcache_sb could take a long time and should be fixed, which should be as simple as replacing it with shrink_dcache_parent; shrink_dcache_anon. But I'm still puzzled as to why a long dcache LRU slows down unmounting. Can you give more details? Thanks, NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
