Messages in this thread | | | Date | Fri, 22 Oct 2010 13:48:34 +1100 | From | Nick Piggin <> | Subject | Re: Inode Lock Scalability V7 (was V6) |
| |
On Fri, Oct 22, 2010 at 01:41:52PM +1100, Nick Piggin wrote: > The locking in my lock break patch is ugly and wrong, yes. But it is > always an intermediate step. I want to argue that with RCU inode work > *anyway*, there is not much point to reducing the strength of the > i_lock property because locking can be cleaned up nicely and still > keep i_lock ~= inode_lock (for a single inode).
The other thing is that with RCU, the idea of locking an object in the data structure with a per object lock actually *is* much more natural. It's hard to do it properly with just a big data structure lock.
If I want to take a reference to an inode from a data structre, how to do it with RCU?
rcu_read_lock() list_for_each(inode) { spin_lock(&big_lock); /* oops, might as well not even use RCU then */ if (!unhashed) { iget(); } }
| |