Re: [PATCH] NFS: Fix RCU warnings in nfs_inode_return_delegation_noreclaim() [ver #2]

From: David Howells
Date: Tue Apr 06 2010 - 15:34:36 EST

Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> wrote:

> OK, just to make sure I understand you... You are asking for two additional
> RCU API members:
> 1. rcu_access_pointer() or some such that includes ACCESS_ONCE(),
> but not smp_read_barrier_depends(), which may be used when
> we are simply examining the value of the RCU-protected pointer
> (as in the NFS case). It could also be used when the
> appropriate update-side lock is held, but for that we have:
> 2. rcu_dereference_protected() or some such that includes neither
> ACCESS_ONCE() nor smp_read_barrier_depends(), and that may
> only be used if updates are prevented, for example, by holding
> the appropriate update-side lock.
> Does this fit?

Yep. I think so.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at