From: Kirill Tkhai <ktkhai@virtuozzo.com> To: dledford@redhat.com, jgg@ziepe.ca, davem@davemloft.net, pablo@netfilter.org, kadlec@blackhole.kfki.hu, fw@strlen.de, pshelar@ovn.org, johannes@sipsolutions.net, paul@paul-moore.com, sds@tycho.nsa.gov, eparis@parisplace.org, jmorris@namei.org, serge@hallyn.com, leon@kernel.org, yuval.shaia@oracle.com, parav@mellanox.com, danielj@mellanox.com, ktkhai@virtuozzo.com, majd@mellanox.com, nicolas.dichtel@6wind.com, vyasevic@redhat.com, paulmck@linux.vnet.ibm.com, vyasevich@gmail.com, gregkh@linuxfoundation.org, daniel@iogearbox.net, jakub.kicinski@netronome.com, ast@kernel.org, brouer@redhat.com, linux@rasmusvillemoes.dk, john.fastabend@gmail.com, dsahern@gmail.com, jiri@mellanox.com, idosch@mellanox.com, vvs@virtuozzo.com, avagin@virtuozzo.com, roman.kapl@sysgo.com, lucien.xin@gmail.com, christian.brauner@ubuntu.com, jbenc@redhat.com, pombredanne@nexb.com, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, dev@openvswitch.org, linux-wireless@vger.kernel.org, selinux@tycho.nsa.gov, linux-security-module@vger.kernel.org Subject: [PATCH net-next 2/5] net: Don't take rtnl_lock() in wireless_nlevent_flush() Date: Thu, 29 Mar 2018 19:20:44 +0300 [thread overview] Message-ID: <152234044431.19153.15864418521565135021.stgit@localhost.localdomain> (raw) In-Reply-To: <152234005959.19153.17907173734141707348.stgit@localhost.localdomain> This function iterates over net_namespace_list and flushes the queue for every of them. What does this rtnl_lock() protects?! Since we may add skbs to net::wext_nlevents without rtnl_lock(), it does not protects us about queuers. It guarantees, two threads can't flush the queue in parallel, that can change the order, but since skb can be queued in any order, it doesn't matter, how many threads do this in parallel. In case of several threads, this will be even faster. So, we can remove rtnl_lock() here, as it was used for iteration over net_namespace_list only. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> --- net/wireless/wext-core.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/net/wireless/wext-core.c b/net/wireless/wext-core.c index 544d7b62d7ca..5e677dac2a0c 100644 --- a/net/wireless/wext-core.c +++ b/net/wireless/wext-core.c @@ -347,8 +347,6 @@ void wireless_nlevent_flush(void) struct sk_buff *skb; struct net *net; - ASSERT_RTNL(); - down_read(&net_rwsem); for_each_net(net) { while ((skb = skb_dequeue(&net->wext_nlevents))) @@ -412,9 +410,7 @@ subsys_initcall(wireless_nlevent_init); /* Process events generated by the wireless layer or the driver. */ static void wireless_nlevent_process(struct work_struct *work) { - rtnl_lock(); wireless_nlevent_flush(); - rtnl_unlock(); } static DECLARE_WORK(wireless_nlevent_work, wireless_nlevent_process);
WARNING: multiple messages have this Message-ID (diff)
From: ktkhai@virtuozzo.com (Kirill Tkhai) To: linux-security-module@vger.kernel.org Subject: [PATCH net-next 2/5] net: Don't take rtnl_lock() in wireless_nlevent_flush() Date: Thu, 29 Mar 2018 19:20:44 +0300 [thread overview] Message-ID: <152234044431.19153.15864418521565135021.stgit@localhost.localdomain> (raw) In-Reply-To: <152234005959.19153.17907173734141707348.stgit@localhost.localdomain> This function iterates over net_namespace_list and flushes the queue for every of them. What does this rtnl_lock() protects?! Since we may add skbs to net::wext_nlevents without rtnl_lock(), it does not protects us about queuers. It guarantees, two threads can't flush the queue in parallel, that can change the order, but since skb can be queued in any order, it doesn't matter, how many threads do this in parallel. In case of several threads, this will be even faster. So, we can remove rtnl_lock() here, as it was used for iteration over net_namespace_list only. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> --- net/wireless/wext-core.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/net/wireless/wext-core.c b/net/wireless/wext-core.c index 544d7b62d7ca..5e677dac2a0c 100644 --- a/net/wireless/wext-core.c +++ b/net/wireless/wext-core.c @@ -347,8 +347,6 @@ void wireless_nlevent_flush(void) struct sk_buff *skb; struct net *net; - ASSERT_RTNL(); - down_read(&net_rwsem); for_each_net(net) { while ((skb = skb_dequeue(&net->wext_nlevents))) @@ -412,9 +410,7 @@ subsys_initcall(wireless_nlevent_init); /* Process events generated by the wireless layer or the driver. */ static void wireless_nlevent_process(struct work_struct *work) { - rtnl_lock(); wireless_nlevent_flush(); - rtnl_unlock(); } static DECLARE_WORK(wireless_nlevent_work, wireless_nlevent_process); -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2018-03-29 16:20 UTC|newest] Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-03-29 16:20 [PATCH net-next 0/5] Introduce net_rwsem to protect net_namespace_list Kirill Tkhai 2018-03-29 16:20 ` Kirill Tkhai 2018-03-29 16:20 ` Kirill Tkhai 2018-03-29 16:20 ` [PATCH net-next 1/5] net: " Kirill Tkhai 2018-03-29 16:20 ` Kirill Tkhai 2018-03-29 16:20 ` Kirill Tkhai 2018-03-29 16:20 ` Kirill Tkhai [this message] 2018-03-29 16:20 ` [PATCH net-next 2/5] net: Don't take rtnl_lock() in wireless_nlevent_flush() Kirill Tkhai 2018-03-29 16:20 ` Kirill Tkhai 2018-03-29 16:20 ` [PATCH net-next 3/5] security: Remove rtnl_lock() in selinux_xfrm_notify_policyload() Kirill Tkhai 2018-03-29 16:20 ` Kirill Tkhai 2018-03-29 16:20 ` Kirill Tkhai [not found] ` <152234005959.19153.17907173734141707348.stgit-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org> 2018-03-29 16:20 ` [PATCH net-next 1/5] net: Introduce net_rwsem to protect net_namespace_list Kirill Tkhai 2018-03-29 16:20 ` [PATCH net-next 2/5] net: Don't take rtnl_lock() in wireless_nlevent_flush() Kirill Tkhai 2018-03-29 16:20 ` [PATCH net-next 3/5] security: Remove rtnl_lock() in selinux_xfrm_notify_policyload() Kirill Tkhai 2018-03-29 16:21 ` [PATCH net-next 4/5] ovs: Remove rtnl_lock() from ovs_exit_net() Kirill Tkhai 2018-03-29 16:21 ` [PATCH net-next 5/5] net: Remove rtnl_lock() in nf_ct_iterate_destroy() Kirill Tkhai 2018-03-29 16:21 ` [PATCH net-next 4/5] ovs: Remove rtnl_lock() from ovs_exit_net() Kirill Tkhai 2018-03-29 16:21 ` Kirill Tkhai 2018-03-29 16:21 ` Kirill Tkhai 2018-03-29 16:21 ` [PATCH net-next 5/5] net: Remove rtnl_lock() in nf_ct_iterate_destroy() Kirill Tkhai 2018-03-29 16:21 ` Kirill Tkhai 2018-03-29 16:21 ` Kirill Tkhai 2018-03-29 17:48 ` [PATCH net-next 0/5] Introduce net_rwsem to protect net_namespace_list David Miller 2018-03-29 17:48 ` David Miller 2018-03-29 17:48 ` David Miller 2018-03-29 17:48 ` David Miller
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