On Wed, Mar 10, 2010 at 10:07:29PM +0800, Herbert Xu wrote:

On Wed, Mar 10, 2010 at 05:13:18AM -0800, Paul E. McKenney wrote:

quoted

If CONFIG_PROVE_RCU is set, rcu_dereference() checks for rcu_read_lock()
and rcu_dereference_bh() checks for either rcu_read_lock_bh() or BH
being disabled.  Yes, this is a bit restrictive, but there are a few too
many to check by hand these days.

Fair enough.  We should get those fixed then.  In fact I reckon
most of them should be using the BH variant so we might be able
to kill a few rcu_read_lock's which would be a real gain.

I have -tip commit a898def29e4119bc01ebe7ca97423181f4c0ea2d that
converts some of the rcu_dereference()s in net/core/filter.c,
net/core/dev.c, net/decnet/dn_route.c, net/packet/af_packet.c, and
net/ipv4/route.c to rcu_dereference_bh().

How should we coordinate the removal of the rcu_read_lock() calls?

							Thanx, Paul