[PATCH] netfilter: nf_conntrack: Batch cleanup
From: Vladimir Davydov <hidden>
Date: 2013-03-14 09:40:38
The patch introduces nf_conntrack_cleanup_net_list(), which cleanups nf_conntrack for a list of netns and calls synchronize_net() only once for them all. This should reduce netns destruction time. -- I've measured cleanup time for 1k dummy net ns. Here are the results: <without the patch> # modprobe nf_conntrack # time modprobe -r nf_conntrack real 0m10.337s user 0m0.000s sys 0m0.376s <with the patch> # modprobe nf_conntrack # time modprobe -r nf_conntrack real 0m5.661s user 0m0.000s sys 0m0.216s Signed-off-by: Vladimir Davydov <redacted> Cc: Patrick McHardy <redacted> Cc: "David S. Miller" <davem@davemloft.net> Cc: "Eric W. Biederman" <redacted> --- include/net/netfilter/nf_conntrack_core.h | 1 + net/netfilter/nf_conntrack_core.c | 46 ++++++++++++++++++++--------- net/netfilter/nf_conntrack_standalone.c | 16 ++++++---- 3 files changed, 43 insertions(+), 20 deletions(-)
diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h
index 930275f..fb2b623 100644
--- a/include/net/netfilter/nf_conntrack_core.h
+++ b/include/net/netfilter/nf_conntrack_core.h@@ -27,6 +27,7 @@ extern unsigned int nf_conntrack_in(struct net *net, extern int nf_conntrack_init_net(struct net *net); extern void nf_conntrack_cleanup_net(struct net *net); +extern void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list); extern int nf_conntrack_proto_pernet_init(struct net *net); extern void nf_conntrack_proto_pernet_fini(struct net *net);
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index c8e001a..09c02ef 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c@@ -1364,30 +1364,48 @@ void nf_conntrack_cleanup_end(void) */ void nf_conntrack_cleanup_net(struct net *net) { + LIST_HEAD(single); + + list_add(&net->exit_list, &single); + nf_conntrack_cleanup_net_list(&single); +} + +void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list) +{ + int busy; + struct net *net; + /* * This makes sure all current packets have passed through * netfilter framework. Roll on, two-stage module * delete... */ synchronize_net(); - i_see_dead_people: - nf_ct_iterate_cleanup(net, kill_all, NULL); - nf_ct_release_dying_list(net); - if (atomic_read(&net->ct.count) != 0) { +i_see_dead_people: + busy = 0; + list_for_each_entry(net, net_exit_list, exit_list) { + nf_ct_iterate_cleanup(net, kill_all, NULL); + nf_ct_release_dying_list(net); + if (atomic_read(&net->ct.count) != 0) + busy = 1; + } + if (busy) { schedule(); goto i_see_dead_people; } - nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size); - nf_conntrack_proto_pernet_fini(net); - nf_conntrack_helper_pernet_fini(net); - nf_conntrack_ecache_pernet_fini(net); - nf_conntrack_tstamp_pernet_fini(net); - nf_conntrack_acct_pernet_fini(net); - nf_conntrack_expect_pernet_fini(net); - kmem_cache_destroy(net->ct.nf_conntrack_cachep); - kfree(net->ct.slabname); - free_percpu(net->ct.stat); + list_for_each_entry(net, net_exit_list, exit_list) { + nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size); + nf_conntrack_proto_pernet_fini(net); + nf_conntrack_helper_pernet_fini(net); + nf_conntrack_ecache_pernet_fini(net); + nf_conntrack_tstamp_pernet_fini(net); + nf_conntrack_acct_pernet_fini(net); + nf_conntrack_expect_pernet_fini(net); + kmem_cache_destroy(net->ct.nf_conntrack_cachep); + kfree(net->ct.slabname); + free_percpu(net->ct.stat); + } } void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls)
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 6bcce40..6c69fbd 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c@@ -545,16 +545,20 @@ out_init: return ret; } -static void nf_conntrack_pernet_exit(struct net *net) +static void nf_conntrack_pernet_exit(struct list_head *net_exit_list) { - nf_conntrack_standalone_fini_sysctl(net); - nf_conntrack_standalone_fini_proc(net); - nf_conntrack_cleanup_net(net); + struct net *net; + + list_for_each_entry(net, net_exit_list, exit_list) { + nf_conntrack_standalone_fini_sysctl(net); + nf_conntrack_standalone_fini_proc(net); + } + nf_conntrack_cleanup_net_list(net_exit_list); } static struct pernet_operations nf_conntrack_net_ops = { - .init = nf_conntrack_pernet_init, - .exit = nf_conntrack_pernet_exit, + .init = nf_conntrack_pernet_init, + .exit_batch = nf_conntrack_pernet_exit, }; static int __init nf_conntrack_standalone_init(void)
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1.7.1