> On Fri, 23 Feb 2007 07:35:38 +0100 Ingo Molnar <[EMAIL PROTECTED]> wrote: > i just got the lockdep warning below when doing: > > echo 3 > /proc/sys/vm/drop_caches > > is this a known quirk in the drop_caches code?
It is - we're taking inode_lock at just the wrong level there and I don't know how to fix it. The basic problem is that we're doing a list_head walk: if we drop the lock we have to start again. Well, I do know how to fix it: rip the various inode lists and use a tagged radix tree instead - make writeback's per-superblock inode walk work the same as writeback's per-inode page walk. That will also alow us to drop the lock and then resume the drop_caches thing at the point where we left off. But it's a large change and has some quite tricky issues which need to be carried over from the existing code and I don't have time to do it. The only (lame) thing I can say for now is that drop_caches is a debug-only, root-only thing :( - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
