On Mon, Feb 11, 2008 at 01:17:38PM -0800, Andrew Morton wrote: > On Mon, 11 Feb 2008 10:38:42 -0800 > Harvey Harrison <[EMAIL PROTECTED]> wrote: > > > All users are gone, remove definitions and comments referring > > to them. > > I'm still showing occurrences in: > > ./Documentation/RCU/NMI-RCU.txt > ./Documentation/kprobes.txt > ./Documentation/uml/UserModeLinux-HOWTO.txt > ./kernel/rcupdate.c > > The last one is interesting: > > /* FASTCALL no longer exists, this wrapper may no longer be needed */ > static void wakeme_after_rcu(struct rcu_head *head) > { > struct rcu_synchronize *rcu; > > rcu = container_of(head, struct rcu_synchronize, head); > complete(&rcu->completion); > } > > The comment is rather ungrammatical/meaningless. Perhaps it is trying > to tell us that we can remove this function now?
Hmmm... A better comment might be something like "Awaken the corresponding synchronize_rcu() instance now that a grace period has completed". Given that the underlying RCU implementation provides callbacks, synchronize_rcu() will need some sort of callback function. So, the question is whether "complete()" can be that callback function. As near as I can tell, the answer is "no", because the RCU callback function always gets a pointer to a struct rcu_head, which would not make much sense to the "complete()" function. In short, I believe that wakeme_after_rcu() needs to stick around. A better comment for wakeme_after_rcu() would be good, perhaps as shown below. Thanx, Paul Signed-off-by: Paul E. McKenney <[EMAIL PROTECTED]> --- rcupdate.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff -urpNa -X dontdiff linux-2.6.24/kernel/rcupdate.c linux-2.6.24-wakeme-comment/kernel/rcupdate.c --- linux-2.6.24/kernel/rcupdate.c 2008-01-24 14:58:37.000000000 -0800 +++ linux-2.6.24-wakeme-comment/kernel/rcupdate.c 2008-02-11 17:47:11.000000000 -0800 @@ -601,7 +601,10 @@ struct rcu_synchronize { struct completion completion; }; -/* Because of FASTCALL declaration of complete, we use this wrapper */ +/* + * Awaken the corresponding synchronize_rcu() instance now that a + * grace period has elapsed. + */ static void wakeme_after_rcu(struct rcu_head *head) { struct rcu_synchronize *rcu; -- 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/