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 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
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