On Fri, Aug 20, 2010 at 10:16:23AM -0400, yao zhao wrote: > On Fri, Aug 20, 2010 at 10:05 AM, Eric Dumazet <eric.dumazet@xxxxxxxxx> wrote: > > Le vendredi 20 août 2010 à 21:44 +0800, Changli Gao a écrit : > >> On Fri, Aug 20, 2010 at 9:33 PM, Simon Horman <horms@xxxxxxxxxxxx> wrote: > >> > Signed-off-by: Simon Horman <horms@xxxxxxxxxxxx> > >> > > >> > --- > >> > > >> > I'm still getting my head around RCU, so review would be greatly appreciated. > >> > > >> > It occurs to me that this code is not performance critical, so > >> > perhaps simply replacing the rwlock with a spinlock would be better? > >> > > >> > Index: nf-next-2.6/net/netfilter/ipvs/ip_vs_sched.c > > > > > >> > - write_unlock_bh(&__ip_vs_sched_lock); > >> > + list_del_rcu(&scheduler->n_list); > >> > + spin_unlock_bh(&ip_vs_sched_mutex); > >> > >> Need a rcu_barrier_bh(). > >> > >> > > >> > /* decrease the module use count */ > >> > ip_vs_use_count_dec(); > > > > > > Quite frankly, if this is not performance critical, just use the > > spinlock (and dont use 'mutex' in its name ;) ) > > > if it is not performance critical, you should use the > read_lock/write_lock, it should make the readers happier than > spinlock. The whole point of the exercise is to stop using read_lock/write_lock because they are generally slower than a spinlock. > the name "mutex" is a little bit confuse. > synchronize_rcu() is not necessary when you only need to delete from a > list as it is atomic. > > > Using RCU here will force at least one RCU grace period at dismantle > > time... > > > > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe netdev" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > yao -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
