On Sun, Apr 29, 2018 at 10:20:33PM -0700, Josh Triplett wrote: > On Mon, Apr 30, 2018 at 02:31:30PM +1000, NeilBrown wrote: > > list_for_each_entry_from_rcu() is an RCU version of > > list_for_each_entry_from(). It walks a linked list under rcu > > protection, from a given start point. > > > > It is similar to list_for_each_entry_continue_rcu() but starts *at* > > the given position rather than *after* it. > > > > Naturally, the start point must be known to be in the list. > > I'd suggest giving an explicit advisory comment to clarify and suggest > correct usage: > > "This would typically require either that you obtained the node from a > previous walk of the list in the same RCU read-side critical section, or > that you held some sort of non-RCU reference (such as a reference count) > to keep the node alive *and* in the list." > > (Feel free to wordsmith the exact wording, but something like that seems > like it would help people understand how to use this correctly, and make > it less likely that they'd use it incorrectly.) What Josh said! Could you also contrast this with the existing list_for_each_entry_continue_rcu() macro in the header comment as well as in the commit log? Thanx, Paul -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
