Hello, On Mon, 3 Oct 2016, HePeng wrote: > Hello Julian, > Thank you very much for the reply. > > I guess this is the same reason that > instead of using *__ip_vs_conn_get*, > you use *atomic_inc* to the ref of > *cp* in *ip_vs_conn_expire* when fails to unlink *cp*, > since there is no callback is running on other CPUs, the > ref must be large than 0. That is also > one of my questions when I read the code. Yes, ip_vs_conn_unlink() can see refcnt=2 or more in which case it does not change refcnt (1->0) and conn remains hashed. But we have to start the timer again, so the pair atomic_inc+__ip_vs_conn_put_timer is used. It looks safe to call __ip_vs_conn_get, atomic_inc_not_zero will work in this case because while in timer callback refcnt can not go below 1, even if other CPUs call ip_vs_conn_unhash+ ip_vs_conn_hash. But atomic_inc is better. Regards -- Julian Anastasov <ja@xxxxxx>
