On Tue, Jun 09, 2009 at 11:44:23AM -0400, Vlad Yasevich wrote: > Paul E. McKenney wrote: > > On Mon, Jun 08, 2009 at 03:11:43PM +0200, Jesper Dangaard Brouer wrote: > >> On module unload call rcu_barrier(), this is needed as synchronize_rcu() > >> is not strong enough. The kmem_cache_destroy() does invoke > >> synchronize_rcu() but it does not provide same protection. > > > > Good, looks like sctp_v4_del_protocol() invokes call_rcu(), which the > > rcu_barrier() would then wait for. And it looks like sctp_v6_del_protocol() > > does the same for IPv6. > > > > Reviewed_by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> > > > >> Signed-off-by: Jesper Dangaard Brouer <hawk@xxxxxxx> > >> --- > >> > >> net/sctp/protocol.c | 2 ++ > >> 1 files changed, 2 insertions(+), 0 deletions(-) > >> > >> diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c > >> index cb2c50d..79cbd47 100644 > >> --- a/net/sctp/protocol.c > >> +++ b/net/sctp/protocol.c > >> @@ -1370,6 +1370,8 @@ SCTP_STATIC __exit void sctp_exit(void) > >> sctp_proc_exit(); > >> cleanup_sctp_mibs(); > >> > >> + rcu_barrier(); /* Wait for completion of call_rcu()'s */ > >> + > >> kmem_cache_destroy(sctp_chunk_cachep); > >> kmem_cache_destroy(sctp_bucket_cachep); > >> } > > Shouldn't the rcu_barrier call be before sctp_free_local_addr_list()? Hmmm... What sequence of events would lead to a failure if rcu_barrier() is after sctp_free_local_addr_list()? 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
